Behind all the critical decisions of World War II was a preponderance of judgment among those responsible for American strategy that the main effort of the United States in a war with the Axis Powers of Europe and Asia should be made in the European theater and that Germany must be defeated first. This view coincided, naturally enough, with the interests of the European members of the coalition but was based entirely on the estimate that such a course of action would best serve the interests of the United States. It was an American consensus, arrived at only after a long sequence of discussions and decisions which reflect a reorientation of American views, interests, and plans going back to World War I. Made before American entry into World War II, in the context of a world threatened by Axis aggression in Europe and Asia, the judgment that Germany must be defeated first stands as the most important single strategic concept of the war. From it and the painful deliberations that preceded the decision was finally crystallized the war plan known as RAINBOW 5, the plan put into effect when the Japanese struck at Pearl Harbor and the Philippines on that "day of infamy" in December 1941. The present essay is a review of this vitally important process of crystallization. 
 Footnote 1 is basically a "suggested readings" list and is appended to the end of this file. All other footnotes are in close proximity to their point of reference.
American strategical planning in the period immediately following World War I was largely conditioned by the postwar political system and by the wide popular reaction against war. The Versailles Treaty, the Washington Treaties of 1921-1922, and the League of Nations (to which Germany was admitted in 1925) gave promise to the war-weary peoples of the world of an international order in which war would be forever banished. That promise seemed to many to have been fulfilled in 1928 when representatives from most of the nations in the world met at Paris to sign the Kellogg-Briand Pact renouncing war as an instrument of national policy. Though the United States was not a member of the League, American policy was closely and consciously designed to support the actions of the League in its efforts to further world peace.
During these years of disillusion with war, isolationism, and Congressional economy, military planning in the United States was largely theoretical. Germany had just been defeated and stripped of military power. Russia was preoccupied with internal problems and, though
Communism was recognized as a menace, the Bolshevik regime was in no position to engage in military adventures. Neither France nor Italy had sufficient naval force to attempt any major operation the Western Hemisphere and had no reason to do so in any case
Of all the powers in Europe, only Great Britain was theoretically in a position to engage the United States in war with any prospect of success. The British had extensive holdings in the Western Hemisphere from which to launch attacks on American territory and they had enough dreadnoughts and battle cruisers to obtain naval supremacy in the Atlantic. But the possibility of a contest with Britain was extremely remote, for there was no sentiment for war on either side of the Atlantic.
In the Pacific and Far East, the situation was different. Between Japan and the United States there were a number of unresolved differences and a reservoir of misunderstanding and ill will that made the possibility of conflict much more likely in that area than in Atlantic. More over, Japan's position had been greatly strengthened as a result of the war and the treaties that followed. In the view of the planners, the most probable enemy in the foreseeable future was Japan. Thus, U.S. strategic thought in the years from 1919 to 1938 was largely concentrated on the problems presented by a conflict arising out of Japanese aggression against American interests or territory in the Far East.
The preparation of strategic war plans involving joint (i.e. Army and Navy) forces-and for all practical purposes this mean the plans prepared by the American staff-was the responsibility of the Joint Board, predecessor of the Joint Chiefs of Staff. Reorganized in 1919 to correct defects that had become apparent since establishment in 1903, the board consisted of six members. the Army Chief of Staff and the Chief of Naval Operations, their deputies, and the chiefs of the War Plans Divisions of each of the services. To it came all matters that required co-operation between the two services, either by referral or on the initiative of the board itself. It had no executive functions or command authority and until 1939 reported to the War and Navy Secretaries. Its recommendations were purely advisory, and became effective only upon approval by both Secretaries, and, in some cases, by the President himself.
The most notable improvement of the 1919 reorganization was the formation of a Joint Planning Committee to assist the board. Consisting of eight officers, four each from the War Plans Division of the Army and of the Navy, this committee performed the detailed investigation and study required for policy decisions, preparation of war plans, and all other matters involving joint actions of the Army and
Navy. It was, in effect, a working group for the Joint Board and made its reports and recommendations directly to that body.
The problems considered by the Joint Board after World War I varied widely, but the development of joint war plans constituted, as it had from 1903 to 1913, the major work of the board, with most attention being given to a possible war with Japan-called ORANGE in accordance with the system in effect between 1904 and 1939 of designating war plans by colors, each color corresponding to a specific situation or nation. The mandate to Japan of the German islands in the Central Pacific had given that nation numerous bases astride the U.S. Fleet's line of communication and made American defense of the Philippines in the event of war with Japan virtually impossible. Moreover, in the Five Power Naval Treaty of 1922, the United States, Great Britain, France, and Italy had promised not to fortify their Far Eastern possessions in return for a pledge by the Japanese to restrain themselves similarly. By this agreement Japan was virtually assured that the Philippines, Guam, and Hong Kong would not become formidable fortresses threatening the home islands. And although Japan had to accept British and American superiority in capital ships at the Washington Conference of 1922, its naval position in the Pacific improved greatly as a result. In the years that followed, while the United States scrapped ships and Japan built them, the strength of the U.S. Fleet relative to that of Japan so declined that it is doubtful if during the 1920's and 1930's it could have met the later on equal terms in the western Pacific.
The first postwar plan for war in the Pacific, developed between 1921 and 1924, reviewed America's unfavorable strategic position and recognized Japan as the probable enemy. The strategic concept adopted by the planners in the event of hostilities was to fight "an offensive war, primarily naval" with the objective of establishing "at the earliest date American sea power in the western Pacific in strength superior to that of Japan." To do this the United States would require a base in that area capable of serving the entire U.S. Fleet. Since the only base west of Pearl Harbor large enough for this purpose was in Manila Bay, it would be essential, said the planners, to hold the bay in case of war and be ready to rush reinforcements, under naval protection, to the Philippines in time to prevent their capture. To the Army fell the vital task of holding the base in Manila Bay until the arrival of the Fleet, but the major role in any war with Japan would be played by the Navy, for success in the Final analysis depended on sea power.
War Plan ORANGE made no provision for a landing on the Japanese home islands. Japan was to be defeated by "isolation and
harassment," by the disruption of its vital sea communications, and by "offensive sea and air operations against her naval forces and economic life." Presumably it would not be necessary to invade Japan. but the planners recognized that if they could not bring Japan to her knees by these means they would have to take "such further action as may be required to win the war." 
For about fifteen years, the strategic concepts embodied in the ORANGE Plan formed the basis for most American war planning. Variations of the plan were prepared and discussed at length. Every conceivable situation that might involve the United States in a war with Japan, including a surprise air attack on Pearl Harbor, was carefully considered and appropriate measures of defense were adopted. At least half a dozen times between 1924 and 1938, the plan was revised, sometimes in response to military changes and sometimes as a result of Congressional sentiment, or because of the international situation. Each time, all the implementing plans had to be changed. The Army and Navy had their separate ORANGE plans, based on the joint plans and complete with concentration tables, mobilization schedules, and the like. In addition U.S. forces in the Philippines, Hawaii, Panama, and other overseas bases had their joint and service plans, as did the defense sectors and continental commands within the United States. Rarely have plans for a war been so comprehensive and detailed, so complete on every echelon, and so long in preparation.
But the United States never fought this war, for ORANGE was based on a situation that never came to pass. The ORANGE war envisaged by the planners was a war between the United States and Japan alone. Neither side, it was assumed, would have allies or attack the territory of a third power. It was a war that was to be fought entirely in the Pacific, with the decisive action to take place in the waters off the Asiatic coast.
These assumptions by the military strategists of the Army and Navy were entirely justified by the international situation and reflected a reasonable estimate of the most probable threat to American interests, an estimate that was shared by most responsible officials during these years. But the planners did not, indeed could not ignore other possibilities, no matter how remote. Thus, during the same years in which they labored on ORANGE, the joint planners con-
 Joint Army-Navy Basic War Plan ORANGE, 1924, Joint Board (JB) 325, Ser. 228. After numerous drafts, the plan was completed and approved by the Joint Board and the Secretary of the Navy in August 1924 and by the Secretary of War the following month. The Preliminary Estimates of the Situation, Joint War Plan ORANGE, and other relevant studies are filed in War Plans Division (WPD) 368; JB 325, Ser 207; JB 305, Sers. 208 and 209; General Board 425, Ser 1136.
sidered a variety of other contingencies that might require the use of American military forces. Among the most serious, though one of the most unlikely, of these was a war with Great Britain alone (RED) which in the planners' estimate could conceivably arise from commercial rivalry between the two nations, or with Great Britain and Japan(RED-ORANGE). The latter contingency was conceded by all to present the gravest threat to American security, one that would require a full-scale mobilization and the greatest military effort.
In their study of these two contingencies the military planners came to grips with strategic problems quite different from those presented by ORANGE. A war with Japan would be primarily a naval war fought in the Pacific. So far as anyone could foresee, there would be no requirement for large ground armies. There was a possibility, of course, that Japan would attack the Panama Canal, Hawaii, and even the west coast, but no real danger that Japan could seize and occupy any of these places. In the unlikely event of a conflict between Great Britain and the United States, there was a real possibility of invasion of the United States as well as attacks against the Canal and American interests in the Caribbean and Latin American. In such a war, the major threat clearly would lie in the Atlantic.
Plans developed to meet the remote danger of a RED war, in contrast to ORANGE, called for the immediate dispatch of the bulk of the U.S. Fleet to the Atlantic and large-scale ground operation to deprive the enemy of bases in the Western Hemisphere. As in ORANGE, it was assumed that neither side would have Allies among the great powers of Europe and Asia, and no plans were made for an invasion of the enemy's homeland by an American expeditionary force. This was to be a limited war in which the United States would adopt a strategic defensive with the object of frustrating the enemy's assumed objective in opening hostilities.
The problems presented by a RED-ORANGE coalition, though highly theoretical, were more complicated. Here the American strategists had to face all the possibilities of an ORANGE and a RED war-seizure of American possessions in the western Pacific, violation of the Monroe Doctrine, attacks on the Panama Canal, Hawaii, and other places, and, finally, the invasion of the United States itself. Basically the problem was to prepare for a war in both oceans against the two great naval powers, Great Britain and Japan.
As the planners viewed this problem, the strategic choices open to the United States were limited. Certainly the United State did not have the naval strength to conduct offensive operations simultaneously in both the Atlantic and Pacific Oceans; she must adopt a strategic defensive on both fronts or else assume the strategic offensive in one theater
while standing on the defensive in the other. The recommended solution to this problem-and it was only a recommended solution, for no joint war plan was ever adopted-was "to concentrate on obtaining a favorable decision" in the Atlantic and to stand on the defensive in the Pacific with minimum forces. This was based on the assumption that since the Atlantic enemy was the stronger and since the vital areas of the United States were located in the northeast, the main effort of the hostile coalition would be made there. For this reason, the initial effort of the United States, the planners argued, should be in the Atlantic.
A strategic offensive-defensive in a two-front war, American strategists recognized, entailed serious disadvantages. It gave the hostile coalition freedom of action to attack at points of its own choosing, compelled the United States to be prepared to meet attacks practically everywhere, exposed all U.S. overseas possessions to capture, and imposed on the American people a restraint inconsistent with their traditions and spirit. Also it involved serious and humiliating defeats in the Pacific during the first phase of the war and the almost certain loss of outlying possessions in that region.
But the strategic offensive-defensive had definite advantages. It enabled the United States to conduct operations in close proximity to its home bases and to force the enemy to fight at great distance from his own home bases at the end of a long line of communications. Moreover, the forces raised in the process of producing a favorable decision in the Atlantic would give the United States such a superiority over Japan that the Japanese might well negotiate rather than fight the United States alone. "It is not unreasonable to hope," the planners observed, "that the situation at the end of the struggle with RED may be such as to induce ORANGE to yield rather than face a war carried to the Western Pacific." 
This plan for a RED-ORANGE war was admittedly unrealistic in terms of the international situation during the 1920's and 1930's. The military planners knew this as well and better than most and often noted this fact in the draft plans they wrote.  But as a strategic exer-
 Proposed Joint Estimate and Plan-RED-ORANGE, prepared in WPD (Army) and approved by Chief of Staff, 3 June 1930, as basis for joint plan, G-3 Obsolete Plans, Reg. Doc. 245-C. Additional material on RED- ORANGE may be found in same file 245-A through F and in WPD 3202. No joint plan was ever approved.  In 1923, the Army draft of RED-ORANGE started with the statement, "Under existing conditions a coalition of RED and ORANGE is unlikely," and twelve years later the Director of Naval Intelligence, commenting on another draft plan, stated that a RED-ORANGE combination was "highly improbable" in the next decade, if at all. Army Draft RED-ORANGE, 1923, Reg. Doc. 245-F; Ltr. Director ONI to Director WPD, 27 Jun 35, sub: Jt Estimate of Situation, RED-ORANGE, copy in WPD 3202. By 1935, planning for such a war had virtually ended.
cise it was of great value, for it forced the military planners to consider seriously the problems presented by a war in which the United States would have to fight simultaneously in the Atlantic and Pacific Oceans. In an era when most war planning was focused on the Pacific and where Japan seemed the most likely enemy, this experience may have seemed irrelevant. But it was to prove immensely useful in the plans developed for World War II.
By late 1937 the assumptions that had given to ORANGE planning its prime importance during the past decade and a half had become of doubtful validity. International events had created a situation that made it increasingly unlikely that a war between the United States and Japan could be limited to these two nations. Germany, Italy, and Japan had joined hands in the Anti-Comintern Pact, and threats or direct acts of aggression were the order of the day in Europe and Asia. Great Britain and France, still suffering from the prolonged economic crisis of the early 1930's and weakened by domestic conflicts, remained passive in the face of this threat, seeking to avert armed conflict by a policy of appeasement.
In the light of these developments, the Joint Board directed its planners to re-examine the ORANGE plan. In its view, the existing plan was now "unsound in general" and "wholly inapplicable to present conditions." The planners were to develop a new plan which should provide, the board specified, for an initial "position of readiness" along the west coast and the strategic triangle formed by Alaska, Hawaii, and Panama. In addition, the planners were to make "exploratory studies and estimates" of the various courses of action to be followed after the position of readiness had been assumed. Clearly implied in these instructions was the injunction to consider the possibility that the United States might become involved in a European conflict while engaged in offensive operations in the Pacific. 
In less than two weeks, the Joint Planning Committee reported its inability to reach an agreement. The Army members, viewing the uncertain situation in Europe, were reluctant to underwrite offensive operations in the Pacific beyond those essential to the security of the strategic triangle and the west coast. With the European Axis in mind, they pointed out that political considerations might require limited action and purely defensive operations in the Pacific. To uncover vital areas in the Western Hemisphere for an offensive in the far Pacific seemed to the Army planners foolhardy indeed. Thus, their plan provided for purely defensive operations after the assumption by U.S. forces of a portion of readiness.
 Memos, JB for JPC, 10 Nov 37, sub: Joint Basic War Plan ORANGE, JB 325, Ser. 617, and Col. S. D. Embick for WPD, 3 Nov 37, same sub. AG 225.
To the Army planners, the primary problem was to determine the kind of war the United States should fight. Should the situation dictate operations designed only for the defense of the United States or of the Western Hemisphere, then the war in the Pacific might well take on a limited character. It was impossible to determine in advance just what the situation would be, whether the United States would be involved with one or more of the Axis Powers, or even what forces would be available. It might well be, declared the Army planners, that national policy and public opinion would neither require nor support a plan for offensive operations in the Pacific.
The Navy members of the Joint Planning Committee argued that American strategy could not be limited to a purely defensive position in readiness but must aim at the defeat of the enemy. Once war began, production must be quickly increased to provide the means required both for the security of the continental United States and for offensive operations in the Pacific. Should the European Axis give aid to the enemy, the naval planners assumed, with Great Britain clearly in mind, that the United States would have allies who would provide the assistance needed by the U.S. Fleet to maintain naval superiority over Japan. "The character, amount, and location of allied assistance," they hastened to add, "cannot be predicted." 
The separate reports submitted by the Army and Navy members of the Joint Planning Committee put the choice between the opposing strategies squarely up to the Joint Board. The board avoided the choice by issuing new instructions to the planners on 7 December 1937. The new plan, it specified, should have as its basic objective the defeat of Japan and should provide for "an initial temporary position in readiness" for the Pacific coast and the strategic triangle. This last was to be the Army's job; the Navy's task would consist of "offensive operations against ORANGE armed forces and the interruption of ORANGE vital sea communications." 
Even under these revised instructions, the planners were unable to agree on the best way to meet an Axis threat. Faced with another split report, the Joint Board turned over the task of working out a compromise to the Deputy Chief of Staff and the Assistant Chief of Naval Operations. These two, after a month of discussion, finally came up with a new ORANGE plan on 18 February 1938. This plan maintained the traditional offensive strategy in the Pacific, but it also took into account the danger of a simultaneous conflict in the At-
 Ltrs, Army and Navy Members JPC to JB, 28 and 30 Nov 37, sub: Joint Basic War Plan ORANGE, JB 325, Ser 617. The Army plan is in Appendix A, the Navy's in Appendix B. See also, Draft Memo, Col. W. J. Krueger, 22 Nov 37, sub: Some Thoughts on Joint War Plans, AG 225.  Directive, JB to JPC, 7 Dec 37, sub: Joint Basic War Plan ORANGE, JB 325, Ser. 618.
lantic-the first time this possibility was recognized in ORANGE planning. On the outbreak of a war with Japan, the United States would first assume a position in readiness and make preparations for the offensive against Japan. It would then be ready to meet any unexpected development that might arise, including an attack in the Atlantic. If none did, the Navy would then proceed to take the offensive against Japan with operations directed initially against the mandated islands and extending progressively westward across the Pacific. These operations combined with economic pressure (blockade) would, it was believed, result in the defeat of Japan and a settlement that would assure the peace and safeguard American interests in the Far East. 
The 1938 revision of ORANGE, with its emphasis on flexibility, represented an enormous advance in military planning. The Navy's single-minded insistence on an advance into the western Pacific was still present but it was modified by an increased awareness of the uncertainties of a world threatened by the rising tide of Axis aggression. The Army, with its concern for the defense of the United States, was shifting away from the Pacific orientation that had dominated strategic planning since World War I and was turning anxious eyes toward Europe. A RED or a RED-ORANGE war was a theoretical probability no longer worth considering, and the Atlantic area occupied more and more the attention of the strategists. Moreover, all earlier plans had assumed the United States would fight alone; now that the world was becoming divided between two armed camps that assumption might have to be revised.
Though it was the Army planners who seemed most aware of the danger from Europe, it was the Navy that made the first move to strengthen America's Atlantic defenses. In December 1937, the director of the Navy War Plans Division, Capt. Royal E. Ingersoll, was sent to London to discuss informally with the British Admiralty the new construction programs of the two navies and the conditions of U.S.-British naval co-operation in the event both nations were involved in a war against Japan. During the course of these discussions, the possibility of a German war inevitably arose. The British viewed this possibility with concern, for the Germans could be expected to attack British trade routes in the Atlantic. Should Italy join Germany, the prospects were even more alarming. The French, if they entered the war, would hold the western Mediterranean, but the British would
 Joint Basic War Plan ORANGE, 21 Feb 38, JB 325, Ser. 618. The plan was approved by the Secretary of the Navy on 26 February and the Secretary of War two days later.
still have to place the bulk of their forces in the Atlantic. They would have little, therefore, to send to the Far East. Here the United States could perform a valuable service in the common cause by taking up the slack in the Far East in return for the security the Royal Navy would provide in the Atlantic. Even if the United States became involved in the European conflict, Great Britain could still be relied upon to man the Atlantic barrier so long as the U.S. Fleet assumed responsibility for the Pacific. It is perhaps for this reason that the Navy members of the Joint Planning Committee seemed less concerned about the Atlantic and more interested in the Pacific than the Army planners.
Events in Europe in 1938 fully justified the concern of American policy makers and planners, and the Munich crisis in September of that year provided the impetus to a comprehensive review of American strategy. Taking the lead from the public statements of President Roosevelt and Secretary of State Cordell Hull, the Joint Board directed its planning committee in November to make a study of the course the United States should follow if German and Italian aggression in Europe and simultaneous Japanese expansion in the Far East should threaten American security and interests in both the Atlantic and Pacific. 
Here, for the first time, was a specific directive to the planners to study (within the context of the current international situation) the problems presented by a two-ocean war in which the United States, acting in concert with allies, would be opposed by a coalition. These problems had been studied before in the ORANGE-RED plans, but under entirely different assumptions and in a completely unrealistic situation. They had been considered briefly and tangentially also in the latest revision of ORANGE with its provision for a position in readiness and co-operation with allies. The informal naval conversations in London in January 1938 were a clear recognition of the possibility of such a war and the first step toward the intimate military collaboration that marked the Anglo-American relationship during World War II.
For almost six months, the planners of the Joint Board considered the problem presented by simultaneous Axis aggression in the Atlantic and Pacific areas and finally in April 1939 submitted their report. In it they reviewed the world situation, estimated the likelihood of war, calculated the probable objectives of the Axis in Europe and Japan
For an account of the Staff Conversations in London early in 1938, see Pearl Harbor Report, Part 9, pages 4272-78 and Capt. Tracy B. Kittredge, U.S.-British Naval Cooperation, 1939-1945, Section I, Part c, pages 37-38.  Min, JB Mtg, 9 Nov 38.
in the Far East, discussed the effects of concerted action by these powers on the United States, and analyzed the strategic problems involved in the various situations that might result from such action. So comprehensive was the report, such a model of strategic analysis, that it was characterized by the Joint Board as "a monument" to its planning committee and became the basis for much of the strategic planning before Pearl Harbor. 
In their effort to arrive at a sound military strategy for the United States, the joint planners examined the various contingencies that might arise as a result of Axis aggression. On the basis of this examination, they concluded that:
1. Germany and Italy would take overt action in the Western Hemisphere only if Great Britain and France remained neutral or were defeated.
2. Japan would continue to expand into China and Southeast Asia at the expense of Great Britain and the United States, by peaceful means if possible but by force if necessary.
3. The three Axis Powers would act together whenever the international situation seemed favorable. If other countries, including the United States, reacted promptly and vigorously to such action, then a general war might well follow.
The reaction of the United States to these or any other situations that might arise, the planners pointed out, would depend in large measure on the forces available and the extent to which American interests were involved. In the event of a threat in both oceans simultaneously, the United States, they maintained, should assume the defensive in the Pacific, retaining adequate forces based on Hawaii to guard the strategic triangle. Arguing further in a manner reminiscent of RED-ORANGE planning, the strategists of the Joint Board declared that priority in a two-ocean war must go first to the defense of vital positions in the Western Hemisphere-the Panama Canal and the Caribbean area. From bases in that region, the U.S. Fleet could operate in either ocean as the situation demanded, but its primary obligation must always be to control the Atlantic approaches to the Western Hemisphere, especially to the south where the continent was more exposed. This task would not be difficult if Great Britain and France actively opposed Axis aggression, but if they did not the security of the South Atlantic would become the major concern of U.S. forces, and the active co-operation of the Latin American states the indispensable prerequisite for political and military action.
 Min. JB Mtg, 6 may 39; Ltr, JPC Rpt, Exploratory Studies, 21 Apr 39, JB 325, Ser. 634. The discussion of the report is based on the Exploratory Studies and related papers in the same file.
On the basis of their study the joint planners recommended that a series of war plans be prepared, each of them to be applicable to a different situation. Priority in these plans, they held, must be given to the defense of the United States, and this would require safeguarding the security of the Western Hemisphere. To hold firm to these objectives would be no easy task, the planners recognized. Not only must strategy be linked to policy, but it must also take cognizance of such intangibles as tradition, the spirit of the nation, and "emotionalized public opinion."
The pioneering study by the joint planners in 1939 raised sharply and dramatically the question of American policy in the event of concerted aggression by Germany, Italy, and Japan. By focusing on the threat to the Caribbean and South America, the planners challenged strongly the long-standing orientation of American strategy toward the Pacific and gave weight to the Army's arguments against offensive operations in the western Pacific.
The planners raised another issue that needed to be resolved before the course of national policy could be charted. All the color plans had been based on the assumption the United States would act alone. Was this assumption valid in terms of the international situation and in the face of a threatening Axis coalition? Should the strategists in drawing up their plans therefore assume that the United States would have allies? And if so, who would they be and what would we be expected to do for them and they for us? Like the Atlantic versus Pacific issue, this question of allies involved political matters and would have to be resolved by the President himself.
It was perhaps as well that no firm answers were forthcoming in the spring of 1939, for the course of events was still far from clear The planners recognized this when they proposed that alternative plans be prepared to meet different situations in which the United States would have to meet the combined threat of Germany, Italy, and Japan. The Joint Board, in approving the work of the planners, accepted this recommendation and in June 1999 laid down the guide lines for the development of these war plans, aptly designated RAINBOW to distinguish them from the color plans. 
There were to be five RAINBOW plans in all, each of them based on a different situation. The objective of all was the same-to defend the United States and the Western Hemisphere from Axis aggression and penetration, overt or concealed. In developing their plans, the
 The first directive of the Joint Board was dated 11 May 1939, but on further study was revised and amended instructions issued on 30 June. Min, JB Mtgs, 6 May and 30 Jun 39 JB 325, Ser. 634; Ltrs, JB to JPC, 11 May 39, sub: Joint Army and Navy Basic War Plans, RAINBOWS 1, 2, 3, and 4; JPC to JB, 23 Jun 39, same sub; and JB to JPC, 30 Jun 39, same sub, all in JB 325, Ser. 642 and 642-1.
planners were to assume that initially at least the United States would be alone and that the European as well as the Latin American democracies would remain neutral. But in each of the plans they were to "set forth the specific cooperation that should be sought from allied or neutral Democratic Powers, with respect to specific Theaters of Operations to render our efforts fully effective." Common to all of the plans was the assumption that the United States would face a coalition rather than a single power.
The five specific situations forming the basis of the five RAINBOW plans were defined by the Joint Board as follows:
RAINBOW 1 assumed the United States to be at war without major allies. United States forces would act jointly to prevent the violation of the Monroe Doctrine by protecting the territory of the Western Hemisphere north of 10 degrees South Latitude, from which the vital interests of the United States might be threatened. The joint tasks of the Army and Navy included protection of the United States, its possessions and its sea-borne trade. A strategic defensive was to be maintained in the Pacific, from behind the line Alaska-Hawaii-Panama, until developments in the Atlantic permitted concentration of the fleet in mid-Pacific for offensive action against Japan.
RAINBOW 2 assumed that the United States, Great Britain, and France would be acting in concert, with limited participation of U.S. forces in continental Europe and in the Atlantic. The United States could, therefore, undertake immediate offensive operations across the Pacific to sustain the interests of democratic powers by the defeat of enemy forces.
RAINBOW 3 assumed the United States to be at war without major allies. Hemisphere defense was to be assured, as in RAINBOW 1, but with early projection of U.S. forces from Hawaii into the western Pacific.
RAINBOW 4 assumed the United States to be at war without major allies, employing its forces in defense of the whole of the Western Hemisphere, but also with provision for United States Army forces to be sent to the southern part of South America, and to be used in joint operations in eastern Atlantic areas. A strategic defensive, as in RAINBOW 1, was to be maintained in the Pacific until the situation in the Atlantic permitted transfer of major naval forces for an offensive against Japan.
RAINBOW 5 assumed the United States, Great Britain, and France to be acting in concert; hemisphere defense was to be assured as in RAINBOW 1, with early projection of U.S. forces to the eastern Atlantic, and to either or both the African and European Continents; offensive operations were to be conducted, in concert with British and allied forces, to effect the defeat of Germany and Italy. A strategic defensive was to be maintained in the Pacific until success against the European Axis Powers permitted transfer of major forces to the Pacific for an offensive against Japan. 
Of the five plans, RAINBOW 1 was basic, though most limited. Providing for the defense of the Western Hemisphere from the bulge of Brazil to Greenland and as far west as Midway in the Pacific, it es-
 Kittredge, U.S.-British Cooperation, Sec. I, Part D, Notes, pp. 42- 46; Memo, JPC to JB, 23 Jun 39; Min, JB Mtg, 30 Jun 39, JB 325, Ser 642.
tablished the necessary conditions that had to be met before any of the other plans could be executed. RAINBOW 2 and 3 called for offensive operation into the western Pacific, the former on the assumption that Great Britain and France would be allies, and the latter that they would not. In this respect, RAINBOW 3 established virtually the same conditions as the ORANGE plan. RAINBOW 4 also assumed that Great Britain and France would be neutral, presumably as a result of Axis military action, and therefore emphasized the defense of the Western Hemisphere against external aggression. Emphasis in this plan as in RAINBOW 1 was on limited action to fend off any Axis threat to the American Republics. In neither case (RAINBOW 1 or 4) were major U.S. forces to be sent to Europe or to the far Pacific.
The situation envisaged in RAINBOW 5 came closer to the conditions of World War II than any of the others, though these were not foreseen at the time. Like RAINBOW 2, it assumed the active collaboration of Great Britain and France. But unlike that plan, which called for the United States to make the major effort in the Pacific, RAINBOW 5 envisaged the rapid projection of American forces across the Atlantic to Africa or Europe "in order to effect the decisive defeat of Germany, Italy, or both." Clearly implied in this statement was the concept that finally emerged as the basic strategy of World War II: that in a war with the European Axis and Japan Germany was the major enemy and that the main effort therefore should be made in Europe to secure the decisive defeat of Germany at the earliest possible date.
In June 1939 the international situation seemed to point toward the concept outlined under RAINBOW 2, that is, the projection of U.S. forces into the western Pacific with Great Britain and France providing the defenses of the Atlantic. The Navy was particularly interested in this plan, for it would have to carry the major load in any drive across the Pacific. And since the plan assured British and French allies, the Navy would be relieved of some of its responsibilities in the Atlantic to concentrate on the Pacific enemy. At the same time, the United States would have to protect the Far Eastern interests of its allies "as its major share in the concerted effort." Britain's plans for the defense of its Pacific and Asiatic possessions were, therefore, of the utmost importance to the American naval planners.
Captain Ingersoll's visit to London in December 1937 had opened the way for a helpful exchange of information and co-ordinated planning between the American and British staffs. By the summer of 1939 the time seemed ripe for further conversations, and in May an officer of the Admiralty Plans Division came to Washington to talk to the naval planners.
The increasing closeness between American and British naval planning was a vital element in the emergence of an Atlantic-first strategy. From the American point of view, such a strategy and the naval collaboration that flowed from it had a sound basis in national self-interest. Admiral Mahan had pointed this out at the turn of the century and it had become a cardinal principle of American naval doctrine since. In the nineteenth century the Royal Navy alone had controlled the seas, and thus made possible the development of the United States; in the twentieth century, declared Mahan, operation of Great Britain and the United States would assure the safety of the Atlantic community. Together, the two navies could command all the important sea routes of the world.
Policy makers as well as naval officers understood very well the close dependence of American security on British sea power. President Roosevelt had been Assistant Secretary of the Navy from 1913 to 1920 and fully appreciated the importance of sea power to the United States. Control of the Atlantic, he knew, must be always in the hands of friendly powers. That was a fundamental tenet of American policy and no effort would be too great to prevent any potential enemy from gaining command of the Atlantic approaches to the Western Hemisphere. Soon to become British Prime Minister, Churchill understood as well as Roosevelt the implications of naval power for the security of both countries.
The summer of 1939 was one of tense expectancy. Europe was on the verge of war and Japan showed no disposition to abandon aggression in Asia. During these months, a joint RAINBOW 1 plan, which had first priority, was completed and the two services hurriedly pushed forward completion of their own plans for hemisphere defense. 
There were important organizational changes, too, at this time. In an effort to keep in close touch with his military advisers, President Roosevelt, on 5 July 1939, placed the Joint Board under his immediate "supervision and direction." Up to that time, the board, it will be recalled, had reported to the two service Secretaries, under whose authority the board functioned. It now had a broader basis, but still sent its recommendations through the Secretaries, for the President had no desire to alter existing procedures.  This change coincided with a change in the high command.
 Joint War Plan RAINBOW 1, JB 325, Ser. 642-1. Approved by the Joint Board on 9 August, by the Secretary of War and Secretary of Navy on 14 August 1939, and by the President orally two months later.  Military Order, 5 Jul 39; Memo of Secy JB, 20 Jul 39, JB 346, Ser. 646. 1 August, Admiral Harold R. Stark was appointed Chief of Naval Operations to succeed Admiral William D. Leahy, and a month later General George C. Marshall formally succeeded Malin Craig as Chief of Staff of the Army after two months as Acting Chief of Staff.
The outbreak of war in Europe early in September 1939 gave a fresh urgency to RAINBOW planning. RAINBOW 2 seemed to fit the situation of the moment best and while work went forward on the development of plans, the President took measures to strengthen the nation's defenses and to keep America out of war by keeping war away from America. Immediately on the outbreak of hostilities he proclaimed the neutrality of the United States, while ordering the Army and Navy to bring their strength up to the full authorized level. On his initiative. the foreign ministers of the American Republics met at Panama at the end of September to proclaim their neutrality and to devise measures for their joint defense. An American security zone was proclaimed in the western Atlantic, and plans made to patrol the zone to keep war away from the Americas.
Throughout the winter of 1939-1940, the period of the "phony war," the joint planners sought to develop plans to meet the RAINBOW 2 contingency. The task proved a formidable one, indeed, for the range of possibilities was wide. Moreover, each proposed course of action in the Pacific had to be co-ordinated with the plans of the Allies. But without specific knowledge of these, the planners were faced with many uncertainties. In April 1940, therefore, they proposed that conversations should be held with the British, French, and Dutch "as soon as the diplomatic situation permits." By that time, the Army planners had prepared four drafts of a proposed RAINBOW 2 plan, on each of which the Navy had commented in detail. 
The planners were still trying to solve the problems posed by RAINBOW when, in the spring of 1940, the nature of the war in Europe changed abruptly. Early in April German forces invaded Denmark and Norway and by the end of the month had occupied both countries. On 10 May the German campaign against France opened with the attack on the Netherlands and Belgium, and four days later German armor broke through the French defenses in the Ardennes. At the end of the month the British began the evacuation from Dunkerque, and on 10 June Italy declared war. A week later, the beaten and disorganized French Government sued for peace. With France defeated and England open to attack and invasion, the threat from the Atlantic looked real indeed.
In this crisis, American strategy underwent a critical review. Clearly, RAINBOW 2 and 3 with their orientation toward the far Pa-
 The various drafts of RAINBOW 2 can be found in the Army files of the JPC, JB 325, Ser. 642-2.
-cific were scarcely applicable to a situation in which the main thrust seemed to lie in Europe. The defeat of France in June and the possibility that Great Britain might soon fall outweighed any danger that Japanese aggression could present to American security. Calling for an early decision from higher authority, the Army planners argued that since the United States could not fight everywhere-in the Far East, Europe, Africa, and South America-it should limit itself to a single course. Defense of the Western Hemisphere, they held, should constitute the main effort of American forces. In any case, the United States should not become involved with Japan and should concentrate on meeting the threat of Axis penetration into South America. 
The Army's concern about America's ability to meet a possible threat from an Axis-dominated Europe in which the British and French Navies might be employed against the United States was shared by the Navy. As a result, the joint planners began work on RAINBOW 4, which only a month earlier had been accorded the lowest priority, and by the end of May had completed a plan. The situation envisaged now in RAINBOW 4 was a violation of the Monroe Doctrine by Germany and Italy coupled with armed aggression in Asia after the elimination of British and French forces and the termination of the war in Europe. Under these conditions, the United States was to limit its actions to defense of the entire Western Hemisphere, with American forces occupying British and French bases in the western Atlantic. 
Acceptance by the Joint Board of the RAINBOW 4 plan was the beginning rather than the end of the comprehensive review of strategy precipitated by Germany's startling success in Europe. Still in doubt was the fate of Great Britain and the French Navy, and American policy depended to a very large degree on these two unknowns. Possession of the British and French Fleets would give the European Axis naval equality with the U.S. Fleet and make possible within six months hostile operations in the Western Hemisphere. Since six months was the time required to mobilize, equip, and train American forces, the planners asserted that "the date of the loss of the British or French Fleets automatically sets the date of our mobilization." 
During the dramatic weeks of May and June 1940, the President met with his military advisers almost daily and discussed with them
 Memos, WPD for CofS, 22 May 40, sub: National Strategic Decisions, and CofS for WPD, 23 May 40, no sub; Aide-Mémoire, Maj. M. B. Ridgway, 23 May 40, all in WPD 4175-10.  Ltr, JPC to JB, 31 May 40, sub: Joint Army and Navy Basic War Plans-RAINBOW 4. The Joint Board approved the plan early in June and the Secretaries soon after. It was not approved by the President until 14 August. Relevant papers are in JB 325, Ser. 642-4.  Joint RAINBOW 4, JB 325, Ser. 642-4.
every major development of the war. On 13 June, shortly before the fall of France, he called in the intelligence chiefs of the Army and Navy and asked for an evaluation of the situation, posing a number of specific questions. This request precipitated an interim review of the various courses of action open to the United States in the light of the rapidly changing situation. As the planners saw it, there were three alternative courses open:
1. To maintain a strong position in the Pacific and to avoid commitment everywhere else.
2. To make every effort, including belligerent participation, to sustain Great Britain and France.
3. To take whatever measures were required to prevent Axis penetration into the Western Hemisphere. 
All three possibilities had already been considered in one or another of the RAINBOW plans, but, as the planners pointed out, the essence of the problem now was time. RAINBOW 4 was the best course to follow in this situation, in their view, and the end of the British or French resistance, they held, should be the signal for American mobilization.
On the morning of 17 June, the day after the planners had submitted their report, General Marshall discussed the problem with his immediate assistants. "Are we not forced," he asked, "into a question of reframing our naval policy, that is, purely defensive action in the Pacific, with a main effort on the Atlantic side? We have to be prepared," Marshall wrote his staff, "to meet the worst situation that may develop, this is, if we do not have the Allied fleet in the Atlantic." The time had come, he thought, to mobilize the National Guard and to discontinue shipments to England of munitions that would be needed for American mobilization. 
On the basis of this discussion, the Chief of the War Plans Divisions, Brig. Gen. George V. Strong, recommended that same day that the Chief of Staff and the Chief of Naval Operations propose to the President as the basic policy of the United States: first, a purely defensive position in the Pacific; second, no further commitments for material aid to the Allies; and third, immediate mobilization for hemisphere defense. These recommendations reflected the pessimistic and strongly conservative outlook of the Army staff at the time, a view the Army planner made no effort to conceal. His proposal, Strong stated frankly, was "a recognition of our inability to furnish means in quantities sufficient
 Memo, Senior Army and Navy Members JPC to Directors WPD, 16 Jun 40, WPD 4250-3.  Notes on Conference in OCS, 17 Jun 40, Misc Conf, Binder 3.
to affect the situation, and an acknowledgment that we recognize the probability that we are next on the list of Axis powers. . ." 
General Marshall and Admiral Stark approved General Strong's recommendations in principle on 18 June and directed their planners to outline the measures required "to effect an immediate mobilization of national effort for Hemisphere Defense." The result was a comprehensive review of national policy during the latter part of June by the War and Navy Departments, the State Department, and the President. With the study of the questions proposed by Roosevelt on the 13th, this review furnished an estimate of probable war developments and outlined the action required for full-scale mobilization and for aid to Britain and her allies. Though never approved by the President, the conclusions of the planners nevertheless reflected his views and constituted an important milestone in the development of U.S. strategy for World War II. 
The critical point at issue in the discussions was the fate of the French Fleet and the future of Great Britain. The military wished to base their plans on the worst of all possible contingencies-that England, if not the British Empire, would be forced out of the war and that the French Fleet would fall to the Axis. The President, on the other hand, believed that American action should be based on the assumption that Great Britain would remain an active belligerent and that the military situation in Europe would not alter appreciably in the next six months. He did not feel, either, that aid to Britain should be cut off entirely, and countered the planners' arguments with the observation that if a small amount of aid would see the British through without seriously retarding American preparations, then that aid should be furnished. Nor was the President willing to put the armed forces on a wartime basis or to support full mobilization of manpower and industry. He agreed on the necessity for defense of the Western Hemisphere and the protective occupation of European colonial possessions as well as other strategic positions in the Caribbean area and in Central and South America, but only after consultation and negotiation with the other nations concerned.
As a result of these discussions, the planners recommended that American policy be based on the following:
1. That the British Empire would continue to exist in the fall and winter of 1940, though Great Britain itself might not remain an active combatant.
 Memo, WPD for CofS, 17 Jun 40, sub: National Defense Policy, WPD 4250-3.  The relevant papers are filed in WPD 4250-3.
2. That France would be occupied by German forces, and even if the French in North Africa or elsewhere continued resistance, U.S. aid would not alter substantially the French position.
3. That U.S. participation in the war as an active belligerent could not prevent the defeat of France or of Great Britain at this time.
This estimate of the situation at the end of June led the planners to recommend, as the "Basis for Immediate Decisions Concerning the National Defense," a defensive; strategy in the Pacific, regardless of the fate of the French Fleet. But if that fleet did fall into German hands, the planners recognized they would have to consider the question of whether to move the major portion of the U.S. Fleet to the Atlantic. The planners thought, too, that the further release of war materials needed for American forces would seriously weaken the United States. But they did not rule out altogether aid to Britain and stipulated, in accordance with Roosevelt's wishes, that aid would be given "under certain circumstances." 
During the summer of 1940, American policy and strategy were shaped in large measure by President Roosevelt's conviction that Britain must be encouraged to resist and that the British Fleet must not be permitted to fall to Germany. In a real sense, therefore, American strategy was dependent upon British fortunes. Only "one force," said Henry Stimson on the day after France's surrender, "remained between the Nazis and the Western Hemisphere-the British Fleet." If that fleet were lost, the United States would stand alone. 
Reassurances from the British that they had no intention of giving up the fight were gratifying to a President so closely committed to British support, but a more objective estimate of Great Britain's ability to resist invasion and detailed information on which to base plans were needed. To fill this need as well as to see for themselves how the British were fighting and what they needed most, the Army and Navy sent special observers to London in the summer of 1940 at Mr. Churchill's request. The Army observers were General Strong, Chief of the War Plans Division, and Maj. Gen. Delos C. Emmons of the Air Corps. Both would remain for only a few weeks, but the Navy observer, Rear Adm. Robert L. Ghormley, was to remain in London on extended duty. Already, the British had appointed their own Admiralty Committee, headed by Admiral Sir Sidney Bailey, to consider "naval cooperation with the United States Navy" in the event
 Memo, CofS and CNO for President, 27 Jun 40, sub: Basis for Immediate Decisions. ... See also preliminary studies by the planners, with the President's comments, in WPD 4250-3  Stimson and Bundy, On Active Service, pp. 318-19.
of American entry into the war, and had made clear to the Americans in a general way how they intended to fight the war.
With the arrival of the special observers in London in August 1940, the conversations which had been carried on informally by the Navy since December 1937 were broadened to include Army representatives and enlarged in scope to include basic questions of strategy, command arrangements, and materiel requirements. None of the observers doubted the determination of the British people to continue their resistance. In their month in England, Generals Emmons and Strong were greatly impressed by the coolness and confidence of the British under attack, and by the organization, training, and techniques for defense against air attack.  The British faith in the efficacy of air bombardment, and the independent position of the Royal Air Force had an effect also on the two Army observers. Implicit in their report war a reflection of the British belief that Germany could be so weakened ultimately by bombardment as to make ground operations on the Continent feasible.
The American observers also learned much about British strategy for the conduct of the war. In broad terms, the British chiefs outlined for the American observers their policy for the conduct of the war:
1. The security of the United Kingdom and Imperial possessions and interests.
2. Command of the home waters and the eastern Mediterranean, while seeking to regain command of the entire Mediterranean.
3. An intensified air offensive and economic pressures against both Germany and Italy.
4. Development of resources for major offensive ground operations when opportunity offered. 
As to the Far East, the British admitted frankly that their interests would be best served if the U.S. Fleet remained in the Pacific. Their original plan had been to send a naval force to the Far East in the event of a Japanese attack, but that war no longer possible. On the other hand, if Japan came into the war and if the United States sent a portion of the fleet into the Atlantic, British surface vessels from the home fleet and the force at Gibraltar could be sent to the Far East. "The support of the American battle fleet," observed
 For a complete account of these developments and naval conversations, see Kittridge, U.S.-British Naval Cooperation, Section III, Parts A and B.  Memo, Emmons and Strong for CofS, 22 Sep 40, sub: Observations in England, WPD 4368.  Minutes of the Meeting with the British are in WPD 4402-1.
the Chief of the Air Staff, "would obviously transform the whole strategical situation in the Far East."
On the question of American material aid, the British were equally frank. In response to a question from Admiral Ghormley as to whether the British were relying on economic support and eventual co-operation of the United States, they replied that in plans for the future "we were certainly relying on the continued economic and industrial cooperation of the United States in ever-increasing volume." These,
they declared, "were fundamental to our whole strategy." But on the question of the "eventual active cooperation" of the United States, the British were somewhat evasive. "No account had been taken" of this possibility, they told the American observers, "since this was clearly a matter of high political policy."
For the British, Germany clearly was the main enemy and the "mainspring" of the Axis effort in Europe. Arguing from this basis, the British insisted that "whatever action may be necessary against any other country must, therefore, be related to our main object, which is the defeat of Germany"-a statement that came very close to the basic strategic decision of World War II. And when Admiral Ghormley asked the British how they expected to achieve this goal and whether the final issue would be decided on land, they replied that "in the long run it was inevitable that the Army should deliver the coup de grace." But they hoped that the Army's task could be made considerably easier by "a serious weakening in the morale and fighting efficiency of the German machine, if not a complete breakdown." How this would be accomplished the British did not specify, but their emphasis on bombardment indicated that air power would certainly play a leading role in the weakening of Germany.
Events in Europe after June 1940 gave hope for a brighter future than had seemed possible after the German offensives in April and May. The success of the British in beating off the attacks of the Luftwaffe and the reports of the special observers led to a more favorable program of support for the British war effort and to other measures of aid such as the transfer of fifty old destroyers in return for a lease on air and naval base sites in British possessions in the western Atlantic. For the moment, the Axis threat in Europe seemed to be blunted and the way opened for co-operation with the British in the Far East.
But the summer calm gave way to the storms of September. On the 22d of the month, Japanese troops entered northern Indochina,
and five days later the Japanese Government announced it adherence to the Rome-Berlin Axis. Just two days before the signing of the Tripartite Pact, the Army planners had completed a report on the ability of the United States to cope with the problems presented by the Axis threat. After reviewing the possibilities in Europe, the planners pointed out that the United States might soon face renewed advances in the Far East, possibly against the Netherlands Indies, or the Philippines, but that it would not be possible to oppose such moves by a major effort in the Pacific in view of the greater danger in the Atlantic. Operations in the Pacific, they maintained, should be held to the minimum. 
There was general agreement in Washington with this view. The main problem was how to avoid a conflict with Japan and at the same time maintain American interests and defend American possessions in the Far East. The answer perhaps lay in Europe, for there was strong reason to believe that Japan would take no overt military action against the United States or Great Britain until German victory seemed assured. This line of reasoning served to strengthen the view that as long as Great Britain was in danger, the United States should remain on the defensive in the Pacific. It was also a powerful argument for continued aid to Britain and for opposition to any move that might risk serious hostilities with the Japanese.
Early in October the entire subject of American policy toward Japan was reviewed at the highest level in Washington. Inevitably the question of British co-operation arose. The military chiefs opposed strong action on the ground that the British would be unable to send any forces into the area and that the United States could not undertake to assume Allied obligations in the Far East. Despite the well known views of the American staff, the British continued their efforts to persuade the Americans to join in the defense of their Far Eastern possessions by sending naval units to Singapore. In May 1940 Churchill had offered to let the Americans use Singapore "in any way convenient" in order, as he put it, to "keep the Japanese quiet in the Pacific." On 4 October he tried again. In a strong personal message to President Roosevelt discussing the Far Eastern situation, he asked, "Would it not be possible for you to send an American squadron, the bigger the better, to pay a friendly visit to Singapore? There they would be welcomed in a perfectly normal and rightful way." 
Both Admiral Stark and General Marshall were opposed to the dispatch of an American naval force to Singapore and agreed that
 Memo, WPD for CofS, 25 Sep 40, sub: Problem of Production .... WPD 4321-9.  The message is quoted in Churchill, Their Finest Hour, pp. 497-98; see also p. 25.
the greater danger was in the eastern Atlantic. Secretary Hull also opposed the move. As he told the British Ambassador: "It will not be wise, even from the British standpoint, for two wars to be raging at the same time, one in the East and the other in the West. If this country should enter any war, this would immediately result in greatly cutting off military supplies to Great Britain."  The move would be politically inexpedient also, for this was an election year and Roosevelt was already in the midst of a campaign for election to a third term. A military gesture such as Churchill had proposed was likely to lose more votes than it would gain. Thus, on the ground of political expediency as well as strategy, the President turned down Mr. Churchill's invitation.
Developments since the summer of 1940 had made the need for a closer co-ordination of British and American plans increasingly evident. Almost every important problem faced by the military planners raised questions that could not be settled without a knowledge of British capabilities and plans. But the hectic months of a Presidential campaign and the uncertainty of the outcome discouraged any serious effort to lay the basis for such co-ordination. By early November, President Roosevelt's re-election seemed certain and on the eve of the election Admiral Stark made the first bid for a firm and clear statement of American policy that would provide the basis for co-ordinated U.S.-British plans.  It was the most comprehensive analysis thus far of the various courses of action open to the United States, the military effect of developments in Europe and Asia, and the close relationship between British fortunes and American policy. Known as the "Plan Dog" memorandum because the recommended course of action if the United States became a belligerent was contained in paragraph D ("Dog" in military parlance), Admiral Stark's study constitutes perhaps the most important single document in the development of World War II strategy.
The central point of Admiral Stark's analysis was the recognition that American security depended to a very large extent on the fate of Great Britain. This note he sounded at the very outset with the assertion that "if Britain wins decisively against Germany we could win everywhere; but that if she loses the problems confronting us would be very great; and while we might not lose everywhere, we might, possibly, not win anywhere." Should the British Empire collapse, it
 Memoirs of Cordell Hull, I, 906  Memo, Stark for Secy of Navy, 12 Nov 40, no sub. This is a revision of the original 4 November memo, no copies of which are in the Army file, revised to include the Army WPD comments and sent to the President. All papers relevant to this memo are filed in WPD 4175-15.
seemed probable to Stark that the victorious Axis powers would seek to expand their control, economically at first and then politically and militarily, into the Western Hemisphere. The military consequences of a British defeat were so serious for the United States, Stark declared, that Britain ought to be assisted in every way possible. He did not believe, either, that Britain had the manpower or material to conquer Germany. Assistance by powerful allies would be necessary ultimately, and to be ready for this eventuality Britain "must not only continue to maintain the blockade, but she must also retain intact geographical positions from which successful land actions can later be launched."
In facing the consequences of close co-operation with the British, Admiral Stark boldly raised the possibility-thus far avoided-of active American participation in the war. Since Britain could not herself defeat Germany, the question was how American resources in men and supplies could be employed in combination with the British to achieve this end. Admiral Ghormley, it will be recalled, had raised this question with the British in London in August, asking whether large-scale ground operations would be necessary. He had received an affirmative reply from the British then, and Stark now returned to this point. Blockade and bombardment, the means favored by the British, he did not think would do the job. The only certain way of defeating Germany war "by military success on shore," and for that, bases close to the European continent would be required. "I believe," Stark declared, "that the United States, in addition to sending naval assistance, would also need to rend large air and land forces in Europe or Africa, or both, and to participate strongly in this land offensive."
Considering the importance of the Atlantic to American security, Stark argued strongly against major commitments in the far Pacific that would involve the United States in an all-out effort against Pacific such as war envisaged in ORANGE. Such a course would have the effect of drawing resources away from the Atlantic and cutting down aid to Britain. Even a limited war against Japan would require strong reinforcements in the southwest Pacific and southeast Asia to defend British and Dutch possessions. Also, it might prove very difficult indeed to prevent a limited war from becoming unlimited, as the Japanese later found out. Nor did Stark see how the defeat of Japan, even if this could be accomplished, would contribute materially to the more important objectives of the defense of the Western Hemisphere and the continued existence of the British Empire. To perform all the tasks required to achieve there objectives, the United States could "do little more in the Pacific than remain on a strict defensive."
The major alternative courses of action open to the United States, as Stark viewed the possibilities, were four, and he stated them as questions:
A. Shall our principal military effort be directed toward hemisphere defense and security in both oceans? [Similar to RAINBOW 1 and 4.]
B. Shall we prepare for a full offensive against Japan, premised on assistance from the British and Dutch forces in the Far East, and remain on the strict defensive in the Atlantic? [Similar to RAINBOW 2, or Rainbow 3 and ORANGE with allies.]
C. Shall we plan for sending the strongest possible military assistance both to the British in Europe and to the British, Dutch, and Chinese in the Far East? [In effect, this would call for an equal effort on two fronts while defending the Western Hemisphere.]
D. Shall we direct our efforts toward an eventual strong offensive in the Atlantic as an ally of the British, and a defensive in the Pacific? [Similar to RAINBOW 5.]
There was no doubt in Admiral Stark's mind that the alternative outlined in paragraph "Dog" would best serve the national interests. It would enable the United States to exert all its effort in a single direction, make possible the greatest assistance to Britain, and provide the strongest defense of the Western Hemisphere. The one great disadvantage of Plan Dog, of course, was that it would leave Japan free to pursue her program of expansion in Asia and the southwest Pacific. Therefore the United States, while making every effort to avoid war with Japan, should seek to keep that nation from occupying British and Dutch possessions in that area.
Plan Dog was the course to be followed in the event of war-and Stark seemed to have little doubt that the United States would soon be involved in the European conflict. But if war did not come, or, as he put it, "until such time as the United States should decide to engage its full forces in war," the best course to follow would be that outlined in paragraph A, that is, build up the defenses of the Western Hemisphere and stand ready to fight off a threat in either ocean.
Should his proposals find favor with the President, Stark strongly urged measures to put them into effect. The first step would be to prepare a joint plan as a guide for Army and Navy planning, and at least the "skeleton" of alternative plans for other situations that might develop. Such plans, however, would be of limited value if there was not a "clear understanding between the nations involved as to the strength and extent of the participation which may be expected in any particular theater ..." For this reason, therefore, he recommended that secret staff talks be initiated with British military and naval authorities "to reach agreements and lay down plans for promoting unity of allied effort should the United States find it necessary to enter the war." The British had already suggested such conversa-
tions on various occasions, the most recent suggestions having been made in October by the British Ambassador to Secretary Hull in Washington, and by Admiral Sir Dudley Pound to Ghormley in London.
The reaction of General Marshall and the Army planners to Plan Dog was entirely favorable. As a matter of fact, the Army had argued substantially along there lines in June 1940, when the prospect of an Axis victory in Europe had seemed so great, and General Marshall had then asked whether it would not be advisable to reframe U.S. naval policy so as to place the main effort in the Atlantic with "purely
defensive action in the Pacific."  Thus, except for minor comments, the Army planners endorsed the Stark proposals, which went forward to the President on 13 November. On the 18th the Joint Board instructed its planning committee to study the questions raised by Admiral Stark and prepare recommendations for submission to the President and the Secretaries of War and Navy. 
The British, who presumably learned of Plan Dog from Admiral Ghormley, also agreed with Admiral Stark. Since the plan was based so largely on the need to maintain the British Empire, this is not surprising. Churchill thought the plan "strategically sound" and "highly adapted to our interests," as indeed it was, but only because of the identity of British and American interests. He was "much encouraged by the American naval view," and cautioned his staff "to strengthen the policy of Admiral Stark" and "not use arguments inconsistent with it."  Apparently the British chief took this advice seriously for on 23 November Admiral Ghormley reported to Stark that in the view of the Admiralty, which he believed to be the view of the British Government, "the primary objective of the war is the defeat of Germany and Italy," and that in case Japan and the United States should enter the war, U.S.-British strategy in the Pacific should be to contain the Japanese and prevent extension of the operations to the south and to the Indian Ocean.  But the British clung to their faith in Singapore, and still hoped the United States would send a naval force there to hold it against the Japanese.
While arrangements went forward for conversations with the Brit-
 Notes of Conference in OCS, 17 Jun 40, sub: Defense Problems, OCS Misc Conf.  Ltr, CofS to JB, 18 Nov 40, sub: National Defense Policy for the United States, JB 325, Ser. 670; Memos, WPD for CofS, 13 Nov 40, sub: National Policy of the U.S.; Secy Gen Staff for WPD, same date, no sub; and CofS for Secy of War, same date, no sub, all in WPD 4175-15.  Churchill, Their Finest Hour, pp. 690-91. The quotes are from his message of 22 November 1940 to the First Sea Lord.  Ghormley to Stark, 23 Nov 40, quoted in Kittredge, U.S.-British Naval Relations, Sec. II, Part D, p. 313, and Notes, App. B, Records of Admiralty Meeting, 22 Nov 40.
ish, the joint planners continued their efforts to produce a statement of national defense policy based on Admiral Stark's recommendation. If acceptable, this document was to be submitted for approval to the President by the Secretaries of State, War, and Navy and was to serve as the basis for instructions to the American representatives in the forthcoming staff conversations. On 21 December the joint planners completed their work. In all essential respects, their recommendations were similar to those of Admiral Stark. The major objective of U.S. defense policy, they said, was the security of the Western Hemisphere and this war to be secured by full co-operation with the British Commonwealth. Until forced to enter the war, the United States should follow the course advocated in paragraph A of Stark's memorandum; if forced into war with Japan, the United States should at the same time enter the war in the Atlantic and limit operations in the mid-Pacific and Far East so as "to permit prompt movement to the Atlantic of forces fully adequate to conduct a major offensive in that ocean."  American policy and strategy, therefore, would be designed to defeat Germany and its allies in order to prevent the extension of Axis influence into the Western Hemisphere, while seeking to keep the Japanese from entering the war or from attacking British and Dutch territory in the Far East.
The Joint Board approved the work of its planners on 21 December, and the Secretaries of War and Navy gave their approval soon after. The original intention war to have the Secretary of State join the two service Secretaries in submitting there recommendations to the President for his approval as the basis for future action by all agencies of the government. But Mr. Hull refused. He was in general agreement with there policies, he declared, but war doubtful of the propriety of "joining in the submission to the President of a technical military statement of the present situation." 
Arrangements for staff conferences with the British were completed early in January 1941, and on the 15th the British delegation left for the United States. There had been preliminary exchanges of view by cable and a proposed set of instructions prepared for the American representatives. But the military authorities still did not have President Roosevelt's approval of the recommended national defense policy, which was to constitute the guide lines for the American delegates. Finally, on 16 January, the President met with his principal advisers,
 Ltr, JPC to JB, 21 Dec 40, sub: National Defense Policy for the U.S., JB 325, Ser. 670. Earlier drafts and directives are in the same file. See also relevant papers in WPD 4175-15 and JB 325, Ser. 674.  Memo, Brig Gen L. T. Gerow for CofS, 3 Jan 41, sub: Conf with Secy of State, WPD 4175-15.
the two Secretaries and the service chiefs. Present at the meeting also was the Secretary of State. The group came to be known informally as the War Council.
The meeting opened with a consideration of the problems raised by the possibility of simultaneous action by Germany and Japan against the United States. The President thought there was only "one chance in five" of such an attack but he avoided any commitment on the basic question of whether to plan for a major effort in the Atlantic or Pacific. On one point, though, he left no doubt. There was to be no curtailment of aid to Britain, even in the event of a concerted attack in the Atlantic and Pacific. Clearly, the President's major concern was with Great Britain. In that sense, he was of the same mind as his chief military and civilian advisers. He thought the Navy should be prepared to convoy shipping in the Atlantic and continue to patrol the east coast. But he was equally anxious that the Army should not be committed to any operations until it was fully prepared, and that American military policy should be "very conservative" until its strength had been greatly increased. In Latin America, the United States would have to be prepared, the President declared, to provide forces, properly trained, to assist the governments in their resistance to subversive Axis activity.
The President's view of American policy in the Pacific coincided closely with that of the military authorities. There the United States would stand on the defensive with the fleet based on Hawaii. There was to be no naval reinforcement of the Philippines, and the commander of the Asiatic Fleet, based in the Philippines, was to have discretionary authority in the event of attack to withdraw when he thought it necessary. The choice was his and it would be up to him to decide whether to sail east toward Pearl Harbor or south to Singapore, as the British wished. 
By the middle of January 1941, the major lines of American strategy in World War II had emerged and the re-election of President Roosevelt assured a continuation of the policy established during the critical summer months of 1940. While hoping to achieve his aims by measures short of war, the President had publicly stressed during the preceding months America's unreadiness for war and the danger from Europe and the Far East. Army and Navy planners had defined the problem facing the United States in a series of studies and had made plans to meet various situations which might arise. The most likely contingency in early 1941 was that the United States, allied with
 Memo, CofS for WPD, 17 Jan 41, sub: White House Conf of 16 Jan 41, WPD 4175-18.
Great Britain, might be involved in a two-ocean war against a combination of Germany, Italy, and Japan. In such a contingency, it was generally agreed, the United States would adopt a defensive role in the Pacific and make its main effort against the most powerful and dangerous enemy, Germany. But many matters still remained to be decided before firm plans could be made that would best serve the interests of the United States and the free nations of the world. First among these war the necessity for agreement between the United States and Great Britain on how best to secure these objectives.
During the first three weeks of January 1941 the planners of the Joint Board completed their arrangements for the American-British Staff Conference. On 21 January they submitted to the board a proposed agenda for the meetings and a statement of the American position. The meetings were to be nonpolitical; no specific commitments were to be made (except for methods of co-operation) and agreements reached would be subject to approval by the two governments. Within this framework, the delegates were to determine the best methods by which the forces of both nations could defeat Germany and its allies should the United States be "compelled to resort to war"-a phrase introduced by the President; reach agreement on the methods and nature of military co-operation; and co-ordinate plans for the use of their forces.
As a guide for the delegates, American national objectives were defined in virtually the same terms that Admiral Stark used: (1) Protection of the Western Hemisphere against military or political encroachment by any other power; (2) Aid to the British Commonwealth: (3) Opposition by diplomatic means to Japanese expansion. In the event of war, the "broad military objective" of the United States and Britain would be the defeat of Germany, which would be "most effectively attained" by placing the principal military effort in the Atlantic, or "navally in the Mediterranean"-another presidential phrase. In the way of practical advice in negotiating with the British, the delegates were to keep the following in mind:
It is believed that we cannot afford, nor do we need, to entrust our national future to British direction....
United States Army and Navy officials are in rather general agreement that Great Britain cannot encompass the defeat of Germany unless the United States provides that nation with direct military assistance...
It is to be expected that proposals of the British representatives will have been drawn up with chief regard for the support of the British Com-
monwealth. Never absent From British minds are their postwar interests,
commercial and military. We should likewise safeguard our own eventual interests. 
The Joint Board gave its approval to these instructions and procedures on 22 January, submitting them in turn to the Secretaries of
War and the Navy with the suggestion that the statement defining the military position and strategy governing the action of U.S. forces be approved by the President. As a result Secretary Knox personally submitted the report to the President on the 23d and three days later Roosevelt approved it with minor changes in wording. 
The American-British staff conversations opened in Washington on 29 January 1941 and continued through fourteen sessions to 29 March, when the delegates submitted a final report, commonly known as ABC-1.  At the outset, the British stated their position clearly and fully:
1. The European Theater is the vital theater where a decision must first be sought.
2. The general policy should therefore be to defeat Germany and Italy first, and then deal with Japan.
3. The security of the Far Eastern position, including Australia and New Zealand, is essential to the cohesion of the British Commonwealth and to the maintenance of its war effort. Singapore is the key to the defense of these interests and its retention must be assured.
In line with this strategy, U.S. naval Forces, after appropriate dispositions for defense of the Western Hemisphere, should be employed mainly in the Atlantic and Mediterranean, the British stated. But they also declared that the United States should maintain in the Pacific a fleet large enough to prevent the Japanese from prejudicing the main effort in the Atlantic.
There was no disagreement between the Americans and the British on the first two points. Both sides were agreed that Germany was the main enemy and their first objective. They agreed further that the Atlantic would be the decisive theater of the war and the principal effort of the two nations would be made there. The delegates also recognized the legitimate interests of each side, an indispensable basis for co-operation. On the American side, the security of the United
 JPC to JB, 21 Jan 41, sub: Jt Instruction for Army and Navy Representatives... , JB 325, Ser. 674.  Memo, FDR for Secy of Navy, 26 Jan 41, JB 325, Ser. 674; Min, JB Mtg, 22 Jan 41. The changes are noted above.  Papers relating to the meeting are located in OPD Executive Office Files, Item 11, Executive 4, and WPD 4402-1 passim. The report itself is found in several files, but is available in printed form in the Pearl Harbor Attack Hearings, Exhibit 49, Part 15, pages 1485-1542.
States and the defense of the Western Hemisphere were considered of paramount interest, with first call on American forces. British interests were broader, encompassing the security of the British Commonwealth of Nations. "A cardinal feature of British strategic policy," the delegates agreed, "is the retention of a position in the Far East such as will insure cohesion and security of the British Commonwealth and the maintenance of its war effort."
The third point of British strategy, the importance of Singapore involved the whole question of Far Eastern strategy. On this, there was a fundamental disagreement between the British and the American delegates. This disagreement stemmed partly from different national interests. The British had to deal with problems of Commonwealth security, and in their view Singapore was essential to the defense of India, Australia, and New Zealand. American interests in the Far East, though substantial, were not as vital. The only American possession of importance in the area, the Philippines, had virtually been written off as indefensible in a war with Japan.
There was a basic difference in outlook also between the British and Americans. Reflecting their insular position and long tradition in wars against continental powers, the British placed their main emphasis on sea and air power rather than large-scale ground forces The reduction of Germany by these means would be a slow process, but the British were accustomed to long wars and had no doubt of ultimate victory. The final blow, they expected, would be delivered by ground armies, but to prepare for that eventuality they would first secure or regain the strategic positions required for the offensive-Singapore, the Mediterranean-and then concentrate on weakening the enemy's war machine. Victory with minimum losses and minimum risks, exploitation of superior naval power and avoidance of large-scale continental operations-that was the classic British strategy.
The Americans, conscious of their overwhelming material power and unwilling to face the prospects of a long war, wished to concentrate all their power at the earliest possible moment against the main enemy. To achieve this aim and end the war quickly with fewer casualties in the long run, they were willing to face the temporary loss of strategic positions like the Philippines and to risk substantial casualties initially rather than disperse their forces or adopt a purely defensive or delaying strategy.
These differences emerged sharply in the discussions over Singapore. What the British were asking the Americans to do was to underwrite the defense of the Commonwealth and incorporate as a central feature of Allied strategy the British concept of the importance of Singapore as the key to defense of the Far East, even at the ex-
pense of concentrating for a decisive blow against Germany at the earliest possible date. Though the Americans appreciated the political, economic, and symbolic significance of Singapore for the British Commonwealth, they doubted its strategic value and the wisdom of underwriting its defense. To accept the British proposal would not only have been contrary to their instructions but would constitute, the American delegates believed, "a strategic error of incalculable magnitude."  They therefore refused to budge from the position that the British must look after their own special interests, as the United States would look after its own in the Philippines, and that the two nations should act together where their interests coincided, that is, in the North Atlantic and the British Isles.
The report submitted by the American and British delegates laid down the basic guidelines of allied co-operation in World War II. It defined clearly the policies, the "paramount interests" of both countries, and the general strategic concepts designed to support these policies. Among the major strategic objectives accepted by both sides were:
1. The early defeat of Germany, the predominant member of the Axis, the principal military effort of the United States being exerted in the Atlantic and European area, the decisive theater. Operations in other theaters were to be conducted in such a manner as to facilitate the main effort.
2. The maintenance of British and allied positions in the Mediterranean area.
3. The strategic defensive in the Far East, with the U.S. Fleet employed offensively "in the manner best calculated to weaken Japanese economic power, and to support the defense of the Malay Barrier by directing Japanese strength away from Malaysia "
To secure there objectives, the delegates agreed on a number of specific measures, including economic pressure, a sustained air offensive against German military power, the early elimination of Italy from the war, raids and minor offensives at every opportunity, and the support of resistance movements in Axis-dominated countries. All there would be preparatory to the final offensive against Germany. For that it would be necessary to secure baser in the Mediterranean and on the west and northwest shores of Europe, and to gather "maximum land forces, composed largely of mobile armored divisions," to defeat and destroy the German Army.
The agreements reached between the American and British staffs and embodied in ABC-1 were never intended to be binding on the
 Memo, Army Delegates for CofS, 12 Feb 41, sub: Dispatch of U.S. Forces to Singapore, WPD 4402-3.
two nations, or to have any political or official character, but only to determine the way in which the United States and the British Commonwealth could defeat Germany "should the United States be compelled to resort to war." From the start it was understood that conclusions reached by the conferees would have to be confirmed by the Chiefs of Staff of both nations and were contingent upon political agreements by the two governments. In line with this understanding, General Marshall and Admiral Stark gave their tentative approval to the ABC-1 report and advised the British Chiefs that they would present it to the President for approval at an appropriate time.  At the same time the Joint Board issued a new directive for the preparation of plans under RAINBOW 5, the situation most closely meeting the requirements laid down in ABC-1.
Work on RAINBOW 5 had been initiated originally in May 1940, after the German offensive in the west but before the fall of France. In April of that year the Joint Board had established a new priority for the development of RAINBOW plans, placing 5 after 2 and 3.  The situation envisaged then in RAINBOW .5 was a war in which the United States, allied with Great Britain and France, would project its armed forces "to either or both of the African and European continents as rapidly as possible" to accomplish the decisive defeat of Germany. The planning done in May on this basis was rendered obsolete within a month by the fall of France. Moreover, it seemed doubtful at the time that Great Britain would survive, and the planners turned their efforts to other RAINBOW situations-first, RAINBOW 4 (hemisphere defense), and then RAINBOW 3 (United States alone in a major effort against Japan). By the end of 1940, when it appeared that Britain would survive and a revised RAINBOW 5 situation was the most likely contingency to plan for, arrangements were already under way for the American-British Staff conversations.
Once the Chief of Staff and Chief of Naval Operations has given their approval to ABC-1, work on RAINBOW 5 progressed rapidly. By 3O April, the Army and Navy had agreed on a joint plan and on that date submitted their work to the Joint Board. For the purposes of this plan, the allies-Associated Powers, they were called-were assumed to be the United States, the British Commonwealth (less Eire), the Netherlands Indies, Greece, Yugoslavia, China, the Governments-in-Exile, and the Free French; the Axis nations, Germany, Italy, Rumania, Hungary, Bulgaria, and possibly Japan and Thai
 Ltr, CofS and CNO to Special Army and Navy Observers in London, 4 Apr 41, sub: Tentative Approval of ABC-1, WPD 4402-18. See notation on Copy 98, Pearl Harbor Attack Hearings, Part 15, 1485.  Ltr, JPC to JB, 9 Apr 40, sub: Jt Plans-RAINBOW, Approved 10 Apr, JB 325, Ser. 642-1.
land. These last two, even if they were not in the war initially, were potential enemies and the possibility of their intervention was therefore taken into account in the plan. 
RAINBOW 5 was virtually identical with ABC-1. As a matter of fact, one of the first assumptions of the plan was that the allies would conduct the war "in accord with ABC-1" and the arrangements made with the Canadians. Thus, the strategic concepts, supporting measures, and missions enumerated in ABC-1 were repeated almost verbatim in RAINBOW 5. For the U.S. Army, "the primary immediate effort" would be to build up large land and air forces "for major offensive operations against the Axis powers" and other operations were to be restricted to those that would "not materially delay the effort." Just what these operations would consist of was not specified, although reference was made, as in ABC-1, to a large-scale attack by ground forces against Germany and to the capture of bases from which to launch such an offensive. As one of the Army planners explained at the time, "a plan must be formulated upon a situation and no prediction of the situation which will exist when such a plan can be implemented should be made." 
RAINBOW 5 was neither a blueprint for victory nor a plan of operations. It merely outlined the objectives and missions of American forces in case of war on the basis of assumptions that seemed sound at the time. Specific plans to achieve these objectives were still to be made. The first step was to secure authority to proceed.
Joint Board authority came on l4 May when the board formally approved both RAINBOW 5 and ABC-1, which it had tentatively approved early in April. Approval of the Secretaries came on 28 May (Navy) and 2 June (Army), at which time both plans went to the President, with the explanation that the British Chiefs of Staff had approved ABC-1 provisionally and submitted it to their government for approval. The President apparently read the two documents carefully but withheld approval of ABC-1 on the ground that the British had not yet approved it. Nor would he approve RAINBOW 5, presumably because it was based on ABC-1, that is, on arrangements with the British which had not yet been accepted by their government. He did request, however, that "in case of war" the two plans be returned to him for his approval. 
 Ltr, JPC to JB, 30 Apr 41, sub: Joint Basic War Plan-RAINBOW 5, Encl A, JB 325, Ser. 642-5.  Memo, WPD for CofS [May 1941], sub: Analysis of Plans for Overseas Expeditions, cited in Matloff and Snell, Strategic Planning for Coalition Warfare, 1941-1942, pp, 45-46.  Min, JB Mtg, 14 May. The correspondence relating to the approval by the Secretaries and the statement recording the President's reaction are filed in JB 325, Ser. 642-5.
The President's ambiguous response to the carefully worked out arrangements with the British, and to the American plans based on these arrangements, raised the question whether the Army and Navy were authorized to proceed with their own planning for war on a RAINBOW 5 contingency. This question was resolved on 10 June at a meeting in Mr. Stimson's office. General Marshall's view was that since the President had not disapproved the plan, the Army could proceed with its own arrangements. This seemed reasonable, and it was on that basis that the services proceeded to make detailed plans for the employment of their forces. 
Though the President had not given his approval, the decision on the course the United States would follow in the event it was "compelled to resort to war" had, in effect, been made. The United States would make the main effort in the Atlantic and European area where the major enemy, Germany, was located, Just how the final blow would be delivered was not yet known, but the Americans expected it would require a large-scale ground offensive. In the Pacific and Far East, United States strategy would be defensive, with greatest emphasis on the area encompassed by the strategic triangle, Alaska-Hawaii-Panama. Implicit in this concept was acceptance of the loss of the Philippines, Wake, and Guam, Thus, in a period of less than three years, the Pacific orientation of U.S. strategy, developed over a period of many years, was completely reversed. By mid-1941, in response to the threat from Europe, the eyes of American strategists were focused on the Atlantic. It was there, they believed, that the war in which the United States was certain to be involved would be decided.
These expectations were more than fulfilled. Though the war when it came opened with an attack in the Pacific, the President and his military advisers made it clear at the outset in the first of the wartime conferences with the British held at Washington in December 1941-January 1942 (ARCADIA) that they would stand by their decision to defeat Germany first. Not once during the course of the war was this decision successfully challenged.
 Min, Conference OSW, 10 June 41, WDCSA, Secy of War Conf, I.
Louis Morton, Historian with OCMH since 1945, Ph.D., Duke University, Lieutenant Colonel, USAR. Author: Robert Carter of Nomini Hall (Princeton, 1941); The Fall of the Philippines (Washington, 1953), Strategy and Command: Turning the Tide, 1941-1943 (in preparation), (coauthor) Strategy and Command: The Road to Victory, 1943-1945 (in preparation), UNITED STATES ARMY IN WORLD WAR II; numerous articles in military and historical journals; and lectures at National War College, Army War College, and various Service schools and universities.
 In preparing this essay the author has relied principally on the official records found in the Army's files and has cited these wherever applicable. But he owes a large debt also to his colleagues in the Office, Chief of Military History, who have studied these events in their own works, and to many others who have dealt with this complex subject in whole or in part. Among the volumes in the UNITED STATES ARMY IN WORLD WAR II that should be consulted I connection with the present study are: Stetson Conn and Byron Fairchild, The Framework of Hemispheric Defense (in press); Richard M. Leighton and Robert W. Coakley, Global Logistics and Strategy, 1940-1943 (1956); Maurice Matloff and Edwin M. Snell, Strategic Planning for Coalition Warfare, 1941-1943 (1953); Louis Morton, The Pacific War: Strategy and Command, Vol. I (in preparation); Mark Skinner Watson, Chief of Staff: Prewar Plans and Preparations (1950). The official British volume by J. R. M. Butler, Grand Strategy, Vol. II, September 1939-June 1941, is also useful, as are the semiofficial volumes of Samuel Eliot Morison's History of the United States Naval Operations in World War II, The Rising Sun in the Pacific, 1931-April 1942, Vol. III (Boston: Little, Brown and Company, 1948) and The Battle of the Atlantic, September 1939-May 1943, Vol. I (Boston: Little, Brown and Company, 1947). The two volumes of William L. Langer and S. Everett Gleason, The Challenge to Isolation (New York: Harper & Brothers, 1952) and The Undeclared War (New York: Harper & Brothers, 1953), though not official, are based on a thorough study of the State Department records and are an indispensable source for a study of American policy in this period. The reader may also wish to consult a work written from the revisionist point of view, the best statement of which can be found in Charles A. Beard, President Roosevelt and the Coming of the War, 1941 (New Haven: Yale University Press, 1948). Among the most important sources for the present study in the memoir and biographical literature of the period, valuable as a supplement to the official records. Most useful are Winston Churchill, Their Finest Hour (Boston: Houghton Mifflin Company, 1949) and Cordell Hull, The Memoirs of Cordell Hull, 2 vols. (New York: The Macmillan Company, 1948): Robert E. Sherwood, Roosevelt and Hopkins, An Intimate History (New York: Harper & Brothers, 1948); and Henry L. Stimson and McGeorge Bundy, On Active Service in Peace and War (New York: Harper & Brothers, 1948). These works represent only a small proportion of those that may be used with profit, but they should serve as the basis for further investigation into this complex subject.