Before it entered World War II, the United States had committed itself to defend or help defend the entire land area of the Western Hemisphere against military attack from the Old World. In the course of planning for this purpose, the United States Government had defined the hemisphere as including the land masses of North and South America plus Greenland, Bermuda, and the Falklands (but not Iceland or the Azores) in the Atlantic area, and all islands east of the 180th meridian and all of the Aleutians in the Pacific. The armed power of the United States did not prevent minor enemy operations on New World territory, as the Germans in Greenland and the Japanese in the Aleutians demonstrated, but its forces were strong enough by late 1941 to make any major attack on the hemisphere an unprofitable venture for the Axis Powers.
Some Conclusions and Observations
The commitment to defend the whole hemisphere by force was a new departure in the military policy of the United States, although it was a natural outgrowth of American policy and practice under the Monroe Doctrine. It was also a natural extension of the primary mission of the armed forces defense of the homeland. For more than a century the possibility of a serious attack across continental land frontiers had been exceedingly remote, and until the late 1930's an effective attack by land-based airpower was impracticable. Therefore, the Army had concentrated after World War I on protecting the continental United States against attack by sea and against coastal invasion backed by sea power. It was almost equally concerned with the defense of the Panama Canal Zone and Oahu, as the principal outlying bastions for continental defense. By the late 1930's a rapid increase in the range and striking power of aircraft posed a new threat that could become serious if hostile airpower obtained a New World base or bases. The development of airpower coincided with the rise of Adolf Hitler and the secret and formidable preparation of the German nation for war. It was this coincidence that gave birth to the prewar policy of hemisphere defense in 1938, after Hitler had made clear his power and his warlike intent during the Munich crisis. The United States decided that as soon as possible it had to have the means to forestall the establishment of any hostile base on Western Hemisphere territory from
which the continental area or the Panama Canal could be threatened or attacked. To prevent the establishment of enemy bases remained the essence of hemisphere defense during the prewar period of American military preparation from late 1938 to December 1941.
Whatever the United States did for hemisphere defense, it did primarily to safeguard its own national security and interests. As General Embick put it, "In the formulation of all these plans, the vital interests of the United States must be uppermost in our minds."1 The over-all purpose of the new policy, an Army planner noted, was to "deny an enemy bases from which he might launch military operations against any of the democratic nations of this hemisphere"; but its basic design was "to reduce to a minimum the likelihood of accepting war upon our own territory."2 All of the measures planned and taken in the name of hemisphere defense, including those for the salvation of Great Britain and the British life line across the North Atlantic, had the fundamental object of promoting the security of the United States itself.
The basic threat to national security, as conceived by President Roosevelt and Secretary of State Hull from late 1937 onward, was the increasing probability that Germany in combination with Japan might achieve domination over the land masses of the Eastern Hemisphere, wreck the British Commonwealth of Nations, and eventually and almost inevitably threaten the Western Hemisphere with military attack and conquest. The Munich "settlement" gave reality to this specter. Nazi Germany acquired a superior military position for launching an offensive war, and the League of Nations henceforth became completely ineffectual as an instrument for preventing a general war in the Eastern Hemisphere. The amoral leadership of Hitler together with the tremendous lead Germany had over the democratic nations in rearmament made it appear probable by early 1939 that Germany would soon launch an offensive war of unpredictable dimensions.
On the other side of Eurasia, Japan had been engaged since 1937 in the conquest of China, and increasingly the Japanese Government was succumbing to the control of war lords who aimed at Japanese domination of all East Asia and Indonesia. Between 1938 and 1941 these developments made for a constant and serious threat of war between Japan and the United States, though not for a serious Japanese threat to territory in the Western Hemisphere. It was in the realm of possibility only that Japan could establish bases in the Aleutians or western Alaska, in outer islands of the Hawaiian group,
or in islands southwest of Hawaii and east of the 180th meridian. That Japanese aircraft carriers might launch hit-and-run attacks on Hawaii or Panama was a more likely possibility. Since the United States after 1937 kept the bulk of its naval strength in the Pacific, the Army and the government generally tended to discount these dangers to hemisphere territory, and hemisphere defense came to mean very largely Atlantic defense against the menace of Nazi Germany.
President Roosevelt and American military planners foresaw in 1939 that the greatest danger to the United States and to the rest of the hemisphere would be the defeat of France and Great Britain with the surrender or destruction of their naval power. Widespread German influence in Latin America, much of it clandestine and subversive in intent, constituted a more nebulous danger but a serious weakness in the American position. The smashing German victories of 1939 and 1940 naturally bolstered this influence. After France's defeat the Germans planned two specific operations which, if successfully carried out, would have required much more vigorous measures of defense on the part of the United States and the other American nations than were actually put into effect. The Germans planned to invade Great Britain and to sweep through Spain in order to capture Gibraltar and northwest Africa. Hitler's decision to postpone these operations until he had conquered the Soviet Union greatly eased the Atlantic situation in 1941, but did not dissipate American fears for the bulge of Brazil and other New World targets until Germany lost its ability to shift its major war effort from east to west in 1942. The German threat that had most to do with drawing the United States into World War II was the air and sea attack on Great Britain and its North Atlantic life line, which in 1941 turned the military focus of the United States toward the northeast and into the Battle of the Atlantic.
In planning for hemisphere defense after September 1939, the United States assumed that Hitler had embarked on a calculated scheme of world conquest; and in 1941 it assumed that Germany and Japan were acting in close military concert. These were the safe and proper assumptions for military planning. Actually, the Germans and Japanese became associates rather than partners in conquest and did not act in close military concert either before or after Pearl Harbor. Hitler, whatever schemes for world conquest he may have had in mind, never spelled out more than Old World domination (except in what he construed as Japan's proper sphere) and appropriate revenge against the United States for supporting his enemies by such tactics as a bombardment of New York City. Known Japanese plans for conquest were also limited to the Eastern Hemisphere, but unlike Hitler the Japanese, in
furtherance of their plans, felt ready in 1941 to challenge the military power of the United States. After the Japanese unleashed their attack in December, and notwithstanding its unanticipated scope and violence, the United States Government decided that Hitler and German military superiority still posed the greater danger to the national security and to the whole Western way of life, and it reaffirmed its earlier decision that if the nation were drawn into the war it should strive to defeat Germany first.
The seriousness of the German threat in 1940 had led the United States, for the first time in its history, to seek and enter into close military relations with most of the other Western Hemisphere nations. Generally, the other American nations were as aware as the United States of the Nazi menace to democracy, and Canada had almost immediately joined with Great Britain in the war. Inter-American solidarity in World War I furnished some precedents for wartime collaboration, but not for the military staff agreements and defense boards of World War II or for the extensive deployment of United States forces throughout the hemisphere that occurred between 1941 and 1945. In view of the preponderant strength of the United States and its very recent abandonment of intervention, the other American nations entered into these military ties with an understandable concern for their own national sovereignty and interests.
Military relations with Canada differed from those with the Latin American nations, not only because Canada became a belligerent in September 1939 but also because Canada had not participated in the Pan-American gatherings that formulated the basic principles for association with the nations to the south. The close military contacts that developed with Canada in 1940 and 1941 were also tied in with the growing military intimacy of the United States and Great Britain. Thus the Permanent Joint Board on Defense was an immediate outgrowth of the destroyer-base negotiation in August 1940, and joint war plan ABC-22 with Canada was based in large measure on the ABC strategy developed jointly with Great Britain. On the other hand, the prewar and wartime association of the United States and Canada naturally reflected the tradition of the long-unguarded frontier, the economic and demographic intimacy of the two nations, and the precedent of joint boards and commissions created for various purposes during the preceding decades of the twentieth century.
In the area of Latin America, the key to fulfillment of measures for hemisphere defense was the success of the United States both before and after Pearl Harbor in staying within the bounds of its prewar political commitments, which collectively comprised the Good Neighbor policy. By 1938 national
policy was against further territorial expansion in the New World, and the United States had ceased its old political and military interventions in certain Caribbean countries and foresworn intervention for any purpose in any American nation. In general the United States had also committed itself not to "play favorites" among the American nations. That the nation kept within these bounds can be attributed in part to the sound judgment and guidance of Under Secretary of State Welles, who rather frequently prevailed in maintaining them against the wishes of military officers and of President Roosevelt himself.
To have any reality, hemisphere defense required the availability of existing or the development of new military bases. United States plans for hemisphere defense assumed that, when necessary, its forces could use existing military bases and essential supporting facilities in other American nations and in colonial territories of the European powers. Until Pearl Harbor the United States as a matter of policy avoided either the lease or outright acquisition of new base sites in other American nations, and at least in theory avoided exclusive acquisition and use of new bases anywhere except within its own territory. After Pearl Harbor it carefully avoided any use of military bases that could fairly be construed as an infringement on the sovereignty of other New World nations.
A fundamental of the policy and defense plans of the United States was that potential Old World enemies must not obtain control over any territory in the Western Hemisphere, either by force or by negotiation. Germany's victory in the West in 1940 naturally made this a problem of great moment, and the United States prepared to take the steps necessary to prevent British, French, Dutch, and Danish possessions from falling into German hands or under German control. To avoid any pretext for military attack, the United States also opposed the defense of French, Dutch, and Danish possessions by friendly belligerents, and insisted that these lands should be defended as necessary by United States or Latin American forces. As a result of the destroyer-base agreement, the United States also assumed a major share of the responsibility for defending British North Atlantic and Caribbean territories.
As for the territory of the Latin American nations, the United States pledged itself in the staff agreements of 1940 to employ its forces to assist in defeating any external attack by the armed forces of a non-American state or internal attack supported by a non-American state, if the recognized government of the nation concerned asked for such assistance. While the larger Latin nations had sizable military establishments, these were not equipped or trained to meet an Old World enemy force in strength. Nor did the United States
have the means to help equip and train their forces sufficiently or in time to handle major threats from abroad. Therefore, prewar plans for hemisphere defense had to assume that United States forces would be required to defend the Latin American area against major enemy attacks. The large movement of trained Canadian forces to Great Britain made a similar assumption necessary for the northern reaches of the hemisphere. Acting on these assumptions, the United States in military negotiations with other American nations before Pearl Harbor had as its main objectives assured access to existing military base facilities and warnings of impending enemy attacks in time to allow United States forces to reach threatened areas.
In 1939 the war plans of the United States assumed the possibility, and in 1940 the probability, of large-scale military operations in the Western Hemisphere. From the beginning of 1941, although the Army continued to plan the deployment of sizable forces for guarding hemisphere positions to the northeast as well as to the south against external attack, the more immediate apprehension of Army planners was the evil that could be done by Axis fifth columnists in Latin America. By early 1941 the policy of the United States was also veering toward a major war effort across the North Atlantic. The Army recognized that in view of this trend a large defensive deployment of forces to the south would be unsound, and during 1941 it tried to keep the number of combat troops sent into the Caribbean area to a bare minimum. Beyond the Caribbean, it wished only to establish an air reconnaissance base southwest of Panama and to send minimum defense forces to the eastern bulge of Brazil.
The Latin American nations were nevertheless increasingly impressed with the growing military strength of the United States and with the genuineness of its intentions to defend the hemisphere. Understandably, the larger South American nations would have preferred to prepare for a more active role in hemisphere defense than was allotted to them in the war plans of the United States. With their normal European sources of arms and ammunition cut off, these nations looked to the United States for the munitions they needed to rehabilitate and expand their armed forces.
In practice it was impossible for the United States to supply munitions in any quantity to the Latin American nations during 1940 and 1941. In June 1940 the nation had poured a very large part of its surplus of arms into England, and three months later it began a rapid expansion of its own Army forces. During the rest of the prewar period the United States did not have and could not produce the means to arm Latin America and at the same time arm itself and help arm Great Britain, and therefore it staked the safety of the Western
Hemisphere on success in meeting the two last-named objectives. After 1940, if the threat of early and serious attack on South America had become more ominous, the United States probably could and would have allotted more arms to the major states of the southern continent. By late 1942 and 1943, when the nation had the means to supply Latin America with modern arms as well as to meet more pressing needs, the danger to the hemisphere had passed. Nevertheless, before the war ended the War Department had furnished arms to Latin American nations in greater dollar value than planned for them in early 1941 or stipulated for them in lend-lease agreements. The bulk of these arms went to Brazil and Mexico, which became active fighting partners in the war.
The rearmament policies and practices of the United States made inevitable a marked shift in the distribution of military strength within the Western Hemisphere after 1939. In 1939 the active military forces of the other American nations considerably exceeded those of the United States in numbers if not in actual strength. By late 1941 United States forces in the hemisphere not only outnumbered those of the other American nations but greatly exceeded them in effective military power, and this disparity grew progressively greater after the United States entered the war. The shift in military strength within the hemisphere undoubtedly had an appreciable though indeterminable influence on the policies and attitudes of the rest of the Americas, as well as an evident effect on the policies and plans of the United States for the defense of the hemisphere.
By itself, the story of inter-American military relations after 1938 reflects very incompletely the full extent of inter-American cooperation before and after December 1941. The whole New World contributed its economic strength to the preparedness and war efforts of the United States and of the Old World opponents of the Axis nations. The United States in return helped to maintain and improve the material well-being of the rest of the Americas, which had been seriously threatened by the loss of normal Old World markets and sources of supply. Even by itself, the story of inter-American military cooperation for hemisphere defense had a much greater significance than the rather scant dependence of the United States on other American military forces might imply. Without the assurance of effective and friendly local support, any large effort by United States forces in defense of the hemisphere would have been a truly formidable undertaking.
The leaders of the United States Army realized during the prewar years that even under the most auspicious circumstances the Army was ill-prepared for a large-scale hemisphere operation. Out of its nucleus of trained and
equipped troops the Army had to develop a large strategic reserve of units that for the most part would not be ready for action before late 1941. Given this situation, Army planning continued to be dominated by the idea of maintaining a perimeter defense of the citadel, the continental United States. Until 1939 the defense perimeter followed the continental shoreline, and was supported by strong but distant outposts in the Panama Canal Zone and Hawaii. With military expansion and in accordance with the new policy of hemisphere defense, the defensive perimeter was extended outward from the citadel. By mid-1941 it included Greenland, Newfoundland, Bermuda, Puerto Rico, and Trinidad along the Atlantic front and Alaska with Oahu and the Canal Zone along the Pacific. Army planners also wanted to project the perimeter southward to include the Galápagos in the Pacific and, above all, the eastern tip of Brazil in the Atlantic. They believed that with this further extension the perimeter could be held by a minimum number of combat troops, and that no enemy could establish a base for major operations in the Western Hemisphere without first capturing one or more of the perimeter strongpoints.
As long as the United States Navy kept the bulk of its fleet in the eastern Pacific, neither Japan nor any other nation had the capability of establishing a hostile base from which to launch a major operation against the hemisphere's Pacific front, and Nazi Germany with all of its military might could not act similarly in the northern Atlantic as long as the British Fleet was in being and based on the British Isles. In October 1940 General Marshall described the naval aspects of hemisphere defense as "fundamental," and said: "As long as the British fleet remains undefeated and England holds out, the Western Hemisphere is in little danger of direct attack." But, he added, "the situation would become radically changed" if the British Fleet were sunk or surrendered.3
If Britain fell and the British Fleet were lost, it was more than conceivable that the Western Hemisphere might be invaded from the northeast via Newfoundland and the St. Lawrence estuary. This was the threat that aroused the interest of President Roosevelt in acquiring bases for United States forces in Nova Scotia and Newfoundland; it was a matter discussed at the first meeting of the Permanent Joint Board on Defense; and it remained a threat covered by Army expeditionary force plans in 1940 and 1941.
Partly because British and American naval power was stationed so far away, the Army was most concerned during the prewar period with the situation
in the Caribbean area and in eastern South America. The Caribbean Sea and the Gulf of Mexico were the Atlantic approaches to the Panama Canal and also to the "soft underbelly" of the United States itself--its unprotected Gulf coast. Furthermore, two prime strategic materials--oil and bauxite--originated around these seas and traveled through them. After June 1940 the presence in this area of French colonies loyal to the Vichy Government added to the Army's concern.
In South America the bulge of Brazil, closer to Africa than to the nearest of the Antilles, was the one point in the hemisphere vulnerable to large-scale air attack or invasion. Northeast Brazil was undefended, inaccessible to existing Brazilian Army forces, and beyond the range of United States airpower based in the Caribbean area. Even if Britain survived, it seemed to Army planners that Northeast Brazil must be defended by United States forces if German forces moved into western Africa. Furthermore, they held, the effective defense of this one position would insure the whole southern Atlantic front against external attack and reassure all of the Latin American nations against any serious threat from abroad. It was in order to make the Brazilian bulge defensible that the Army arranged with Pan American Airways to construct two chains of airfields leading from the United States to eastern Brazil. But the Brazilians could not be persuaded to request United States Army defenders for the area.
Germany's smashing victories in western Europe in the spring of 1940 had the immediate effect of re-emphasizing hemisphere defense as the basic military policy of the United States. On 23 May President Roosevelt and his principal advisers decided that the nation must avoid war with Japan and concentrate on what they called the "South American situation." Eastern Brazil was the most immediate cause for anxiety, and over the weekend of 25-26 May the President had the Army and Navy engage in hurried planning for a possible expeditionary force to that area. Actually, the services were then unready to carry out any such plan, but they quickly prepared a more comprehensive one for defending the hemisphere on all fronts. This plan, RAINBOW 4, remained the basic guide for American military action until the spring of 1941. After France fell, the President and his principal military advisers reaffirmed the decision to avoid war or offensive action in the Pacific, ruled out intervention in the European war, and decided that the nation must concentrate on mobilizing its manpower and economic strength for hemisphere defense. Underlying these decisions of 24 June was a grave doubt that Great Britain could survive through 1940.
The first breach in the June decisions on national strategy was the agreement with Great Britain to exchange destroyers for bases, concluded on 2 September. During September Army and Navy leaders as well as the President acquired a conviction that Great Britain could hold out at least six months more, and that even if the British Fleet was surrendered in the spring of 1941 it would take the Germans six additional months to make it useful. Therefore, Germany could not launch a major attack across the Atlantic before the autumn of 1941, and by then the United States expected to have a trained and equipped Army of 1,400,000 men as well as greater naval strength. While eventually Germany might muster the strength to challenge the United States, a transatlantic invasion of the hemisphere by German forces within the next two or three years appeared improbable, even if coordinated with a Japanese offensive in the Pacific. With the bounds of neutrality already broken by the destroyer-base exchange, and with a much more optimistic outlook than in June, the United States Government from September onward charted a new course of much greater aid to Great Britain. Eventually and inevitably this new course disrupted plans for a perimeter defense of the hemisphere as plotted in RAINBOW 4.
While Germany stayed its military hand in the autumn and winter of 1940, the United States reached new decisions on national policy. These reaffirmed a defensive posture in the Pacific and concentration on the Atlantic and European situations. But the new policy went much further: it assumed the salvation of Great Britain and the British Fleet, and it contemplated American entry into the European war to defeat Germany. By December 1940 the civilian and military leaders of the War and Navy Departments were convinced that the United States must eventually enter the war against Germany to save itself, and that to save itself it had to save Great Britain. They also agreed that the eventual "big act" in getting into the war would be the one undertaken by United States forces to help protect the North Atlantic seaway to Great Britain.4 President Roosevelt matched these convictions with his conception of lend-lease. In effect, the new orientation of national policy made Great Britain the pivot of measures for defending the nation and the hemisphere during 1941. It also brought the United States Navy into the midst of Atlantic action.
Although the Army was the more active service in preparations for continental and hemisphere defense before 1941, it had actually been playing a secondary role behind a first-line screen of naval power. The Navy much
more than the Army had kept its eyes on the Pacific, where its main strength lay, and where it assumed its main task would be if war came. Nevertheless, as the Army recognized, throughout the prewar years the Navy in conjunction with British naval power was carrying out its primary mission of providing the nation with a first line of defense at a distance. Army leaders were also well aware during these years that only the Navy had a force in being ready for war.
Since 1939 the principal task of the Navy in the immediate defense of the hemisphere had been to maintain a neutrality patrol in Atlantic waters to persuade belligerent warships, and especially German vessels, to keep away from American shores. The Navy had gradually extended its patrol outward into the Atlantic, and the destroyer exchange, though temporarily weakening the patrol, had provided new and improved bases for supporting its operations. Then, in January 1941, President Roosevelt authorized the Navy to prepare for the larger role in the Atlantic of helping to escort American aid to Britain. While the Navy was getting ready for this task, the United States and Great Britain agreed in staff conversations on the course of action they would follow should the United States enter the war, and in March Congress passed the Lend-Lease Act. But when the Navy in April came up with a forthright escort scheme in its Western Hemisphere Defense Plan No. 1, President Roosevelt after some indecision ordered a more circumscribed line of action that confined American naval operations to the western half of the Atlantic and to measures short of escort duty. Even so, it seemed to Army and Navy leaders in the spring of 1941 that the nation was on the brink of open war.
Germany's attack on the Soviet Union in June helped to postpone war in the Atlantic and to precipitate it in the Pacific. Intelligence of the impending German thrust eastward had influenced the decision of President Roosevelt to send American troops to Iceland, and their arrival furnished the justification for escort operations by the United States Navy to the longitude of Iceland. Then in September and October came the "shooting war" and, soon thereafter, escort duties all the way to Britain under the Navy's last Western Hemisphere Defense Plan No. 5.
Whether these successive Navy plans of 1941 were really measures for hemisphere defense was a bone of contention for isolationists then as it has been for some of Mr. Roosevelt's critics since. Granted that the broadening military operations of the United States in the North Atlantic were steps toward the defeat of Hitler's Germany, they were also genuine and effective defense measures. The dual purpose of these Navy plans should be recognized.
Certainly under these plans, and the associated plans of the Army, the United States took its most effective action for Atlantic and hemisphere defense during 1941.
The Army played only a secondary role in the vigorous measures of mid and late 1941 for saving Great Britain and its North Atlantic life line. Execution of these measures meant that the Army could not carry out other plans for defense in the areas for which it had previously felt so much concern the Caribbean and South America. On the other hand, with the North Atlantic increasingly secured and the Germans heavily engaged in the Soviet Union, new Army defense steps to the south had less urgency than before mid-1941. Even some of those already taken had begun to acquire a different character, since the main airway to Brazil was becoming the first stage of an air ferry and supply route to Africa and on to Old World fighting fronts.
The position of President Roosevelt toward hemisphere defense after the spring of 1940 is somewhat difficult to determine from his addresses and other remarks. As a rule, his intimate conversations with advisers were not recorded. From his known remarks and actions it is apparent that after the summer of 1940 Mr. Roosevelt did not feel any acute concern about the possibility of a major military attack on the hemisphere for several years to come. There is no question about the President's detestation of Hitler and the Nazis, nor about his appreciation of how great the threat to the United States would be if Germany secured a dominating position in the Eastern Hemisphere. Nor is there any question about Mr. Roosevelt's determination to use all courses of action that American public opinion would support to stop Hitler.
One of these courses was an appeal to the traditional American doctrine of freedom of the seas. As early as October 1940, the President and Secretary of State Hull had emphasized in public addresses how essential friendly control of the Atlantic and Pacific Oceans was to hemisphere defense. In January 1941 the President began to stress freedom of the seas rather than hemisphere defense as a rallying ground for military preparedness. He also took the position that there should be no "aggressors" peace. Furthermore, he believed that saving Great Britain alone was not enough, because the strength, and security of Britain depended upon the continued support of the rest of the British Empire and its sea communications everywhere. In one of his most revealing utterances the President wrote:
A nationally known advertising man wrote me the other day . . . to suggest that we tell the truth, i.e., that we are not concerned with the affairs of the British Empire but are concerned with our own safety, the security of our own trade, the future of our own
crops, the integrity of our own continent, and the lives of our own children in the next generation.
That, I think, is a pretty good line to take because it happens to be true and it is on that line itself that we must, for all the above purely selfish reasons, prevent at almost any hazard the Axis domination of the world.5
The President's expressed goals clearly called for a larger effort in 1941 than the nation needed to make for the immediate defense of the hemisphere. They also called for a different sort of effort from that which Army planners advocated, as illustrated in discussions about Iceland and the Azores. From the planners' viewpoint it was not necessary nor even desirable to occupy either as a military outpost for the hemisphere; from the President's point of view, both were essential guardians of Atlantic seaways, which had to be controlled to save Britain, and he was convinced that Britain's salvation was an essential to hemisphere and national security.
Until late 1941 the President was apparently more reluctant about getting into the war than were some of his principal advisers. He kept his ears tuned sensitively to American public opinion and opinion polls, and to judge from the public opinion polls Mr. Roosevelt never let the actions of the United States get very far out of step with the opinion of the majority of its people. Several of the President's advisers thought that he lagged behind the majority. Perhaps there was much truth in the remark of a distinguished English observer, who wrote him: "I have been so struck by the way you have led public opinion by allowing it to get ahead of you."6 American opinion remained heavily opposed to any declaration of war until the attack on Pearl Harbor. But in 1940 and 1941 a majority indorsed every action taken in the name of hemisphere defense or freedom of the seas, including the support of Great Britain and military operations in the North Atlantic. The public also approved the action, urged by the President and taken by Congress on 13 November 1941, repealing prohibitions against arming American merchant ships and against allowing them to enter war zones. By that action Congress ended the apparent ambiguity and undercover character of Atlantic operations during the preceding months of 1941 and set the stage for war with Germany.
Then, before a full state of war could develop in the Atlantic, Japan struck in the Pacific: Basically, the United States was no more responsible for Japan's aggression than it had been for Nazi Germany's. The Japanese Government wanted to convert the nations and colonial areas of eastern Asia and Indonesia into subservient tributaries of Japan, and the war in Europe seemed to provide
a golden opportunity for conquest. The Japanese might have been willing to create their so-called Greater East Asia Co-prosperity Sphere by negotiation, but they were not willing to limit their objective. When Great Britain and the United States and the other nations involved decided not to capitulate, Japan cast the die for war.
Until the summer of 1941 new Army measures for defense in the Pacific lagged behind Atlantic preparations. Secretary of War Stimson among others did not believe that Japan would go to war as long as Britain remained undefeated. Alarms in January and July 1941 produced some strengthening of Oahu's Army air defenses and a more rapid garrisoning of Alaska. Since the Army's primary mission in Alaska, Hawaii, and Panama was to guard naval bases and installations, the Navy until August 1941 had the chief voice in determining where Army Pacific reinforcements should go. After that, under the impulse of a new design to contain Japan by airpower, the reinforcement of the Philippines instead of hemisphere outposts became the goal. As a result, some of Hawaii's newly acquired air strength was shifted to the Far East, and the movement of modern aircraft to Alaska was further postponed. The decision to reinforce the Philippines broke through the perimeter concept in the Pacific as the defense of Iceland and Great Britain had broken through it in the Atlantic. The Japanese attacked just as this reinforcement was getting under way.
Japan's astounding success at Pearl Harbor opened the whole western front of the hemisphere to the danger of hit-and-run carrier attacks, and opened some of the Pacific islands within the hemisphere to invasion. Within six months the victory of the United States in the great naval air battle off Midway blunted these threats and limited further Japanese action in the hemisphere to a bothersome occupation of the outer Aleutians. In the western Atlantic, during the first seven months of 1942, German submarines took a tremendous toll of merchant shipping off the East and Gulf coasts of the United States and in the Caribbean Sea. Inter-American solidarity was further cemented when a German attack on Brazilian shipping farther south brought Brazil into the war in August 1942. Three months later the successful invasion of northwest Africa by American and British forces put an end to any justifiable concern for hemisphere defense in the Atlantic.
A glance at the distribution of troops in mid-1942 shows that in the first few months after Pearl Harbor continental and hemisphere defense plans had continued to provide the main guides to the actual deployment of Army ground and air forces, despite the large movement of forces to the Southwest Pacific and smaller movements to the British Isles and Iceland. At the begin-
ning of July 1942, when the Army had about 800,000 officers and men assigned to active theaters and defense commands, Western Hemisphere garrisons and commands contained about three fourths of this strength, divided about equally between defense commands in the continental United States and overseas outposts within the hemisphere. In other words, the Army did not begin to move the bulk of its ready forces across the oceans until after the nation and the hemisphere were reasonably secure. After 1942 the principal task of Army defenders within the hemisphere was to guard outposts that had become bases for the support of overseas offensives.
The focus of Army planning had begun to shift from hemisphere defense to future operations outside the hemisphere long before, in late 1940 and early 1941. During 1941 military men moved somewhat more slowly than political leaders toward the new strategy, partly because the former were more aware than the latter of minimum defense needs and partly because military leaders were painfully aware of the unreadiness of most of the Army until late 1941 for offensive action. Indeed there was a remarkable coincidence between the Army's readiness for limited offensive action and the outbreak of full-scale war. Enough forces were ready in December 1941 so that Army planning and action could turn quickly and naturally to launching operations overseas that would obviate the need for hemisphere defense at home.
Table of Contents ** Previous Chapter (15)
1. Memo, CG Third Army for WPD, 8 Jun 40, WPD 4175-11.
2. Memo for Rcd, Lt Col Anderson, WPD, 1 Nov 39, WPD 4175-2.
3. Résumé of conversation between Gen Marshall and Gen Nicolas Delgado, CofS Paraguayan Army, 31 Oct 40, WPD 4385-1.
4. Stimson Diary, entry of 16 Dec 40.
5. Pers Ltr, President Roosevelt to Senator Josiah W. Bailey, 13 May 41, in FDR Personal Letters, 11, 1154.
6. Pers Ltr, 3 Jun 41, Roosevelt Papers, FDRL.