Between World Wars


Extracted from

Soon after the armistice of November 1918 the War Department urged the Congress to authorize the establishment of a permanent Regular Army of nearly 600,000 and a three-month universal training system that would permit a quick expansion of this force to meet the requirements of a new major war. The Congress and American public opinion rejected these proposals. It was hard to believe that the defeat of Germany and the exhaustion of the other European powers did not guarantee that there would be no major war on land for years to come. Although the possibility of war with Japan was recognized, American leaders assumed that such a war, if it came, would be primarily naval in character. Indeed, the fundamental factor in the military policy of the United States during the next two decades was reliance on the United States Navy as the first line of national defense.


Another basic factor that determined the character of the Army between world wars was the decision of the United States not to join the League of Nations and therefore to reject participation in an active and co-operative world security system to maintain peace. The American people soon showed themselves unwilling to support an Army in being any larger than required to defend the continental United States and its overseas territories and possessions, to keep alive a knowledge of the military arts, and to train inexpensive and voluntary civilian components. Since the Army had huge stocks of materiel left over from its belated production for World War I, the principal concern of the War Department until the 1930's was manpower to fulfill these peacetime missions.




Planning for demobilization had begun less than a month before the armistice, since few in the United States had expected the war to end so quickly. When the fighting in Europe stopped, almost all officers and men in the Army became eligible for discharge. The War Department had to decide how to muster out these men as rapidly and equitably as possible without unduly disrupting the national economy, while at the same time maintaining an effective force for occupation and other postwar duties. It decided in favor of the tradi-




tional method of demobilization by units as the one best calculated to achieve these ends. Units in the United States were moved to thirty demobilization centers located throughout the country, so that men after processing could be discharged near their homes. Units overseas were brought back just as rapidly as shipping space could be found for them, processed through debarkation centers operated by the Transportation Service, and then sent to the demobilization centers for discharge. In practice the unit system was supplemented by a great many individual discharges and by the release of certain occupational groups, notably railroad workers and anthracite coal miners.


In the first full month of demobilization the Army released about 650,000 officers and men, and within nine months it demobilized nearly 3,250,000 without seriously disturbing the American economy. A demobilization of war industry and disposal of surplus materiel paralleled the release of men, but the War Department kept a large reserve of weapons for peacetime or new emergency use. Despite the lack of much advance planning demobilization worked reasonably well. The Army was concerned at the outset because it had no authority to enlist men to replace those discharged. A law of February 28, 1919, permitted enlistments in the Regular Army for either one or three years; and by the end of the year the active Army, reduced to a strength of about 19,000 officers and 205,000 enlisted men, was again a Regular volunteer force.


Immediate Duties


At home during 1919 and 1920 Army forces continued the guard on the border of Mexico required by revolutionary disturbances in that country. Because of the lack of National Guard forces (not yet reorganized) the active Army until the summer of 1921 also had to supply troops on numerous occasions to help suppress domestic disorders, chiefly arising out of labor disputes and race conflicts in a restless postwar America.

Abroad, a newly activated United States Third Army moved into Germany on December 1, 1918, to occupy a segment of territory between Luxembourg and the Rhine River around Coblenz. As many as nine divisions participated in the German occupation during the spring of 1919. Similarly, an Army regiment sent to Italy before the end of hostilities participated for four months in the occupation of Austria. In Germany, American troops had no unusual difficulties with the populace, and soon after the peace conference ended in May 1919 the occupation forces were rapidly reduced. They numbered about 15,000 at the beginning of 1920. After rejecting the Treaty of Versailles the United States




remained technically at war with Germany until the summer of 1921, when a

separate peace was signed. Thereafter, the occupying force was gradually withdrawn, and the last thousand troops left for home on January 24, 1923.


Revolutionary turmoil in Soviet Russia induced President Wilson in August 1918 to direct Army participation in expeditions of United States and Allied forces that penetrated the Murmansk-Archangel region of European Russia and into Siberia via Vladivostock. The north Russian force, containing about 5,000 American troops under British command, suffered heavy casualties while guarding war supplies and communication lines before being withdrawn in June 1919. The Siberian force of about 10,000 under Maj. Gen. William S. Graves had many trying experiences in attempting to rescue Czech troops and in curbing Japanese expansionist tendencies between August 1918 and April 1920. Together these two forces incurred about as many combat casualties as the Army expeditionary force of similar size had sustained in Cuba in 1898. After the withdrawals from Germany and Russia, the only Army forces stationed on foreign soil until 1941 were the garrison of about 1,000 maintained at Tientsin, China, from 1912 until 1938, and a force of similar strength dispatched from the Philippines to Shanghai for five months' duty in 1932. The Marine Corps rather than the Army provided the other small foreign garrisons and expeditionary forces required after World War I, particularly in the Caribbean area.


Reorganization Under the National Defense Act of 1920


After many months of careful consideration, Congress passed a sweeping amendment of the National Defense Act of 1916. The new National Defense Act of June 4, 1920, which governed the organization and regulation of the Army until 1950, has been widely acknowledged to be one of the most constructive pieces of military legislation ever adopted in the United States. It rejected the theory of an expansible Regular Army urged by Army leaders since the days of John C. Calhoun. Instead, it established the Army of the United States as an organization of three components, the professional Regular Army, the civilian National Guard, and the civilian Organized Reserves (Officers' and Enlisted Reserve Corps). Each component was to be so regulated in peacetime that it could contribute its appropriate share of troops in a war emergency. In effect the act acknowledged the actual practice of the United States throughout its history of maintaining a standing peacetime force too small to be expanded to meet the needs of a great war, and therefore necessarily of depending on a new Army of civilian soldiers for large mobilizations. In contrast to earlier practice, the training of civilian components now became a major peacetime




task of the Regular Army, and principally for this reason the Army was authorized a. maximum officer strength of 17,726 more than three times the actual officer strength of the Regular Army before World War I. At least half of the new permanent officers were to be chosen from among non-Regulars who had served during the war. The act also provided that officer promotions, except for doctors and chaplains, were henceforth to be made from a single list, a step that equalized opportunity for advancement throughout most of the Army. The Regular Army was authorized a maximum enlisted strength of 280,000, but the actual enlisted as well as officer strength would depend on the amount of money voted in annual appropriations.


The new defense act also authorized the Army to continue all of its arm and service branches established before 1917, and to add three new branches, the Air Service, the Chemical Warfare Service, and a Finance Department, the first two reflecting new combat techniques demonstrated in the late war. The Tank Corps of World War I, representing another new technique, was absorbed by the Infantry. The act specifically charged the War Department with mobilization planning and preparation for the event of war. It assigned the military aspects of this responsibility to the Chief of Staff and the General Staff and the planning and supervision of industrial procurement to the Assistant Secretary of War.

World War I experience both in Washington and in France had greatly strengthened the position and authority of the General Staff. When General Pershing became Chief of Staff in 1921 he reorganized the War Department General Staff on the model of his wartime General Headquarters staff in France, to include five divisions: G-1 dealing with personnel, G-2 with intelligence, G-3 with training and operations, G-4 with supply, and a new War Plans Division that dealt with strategic planning and related preparations for the event of war. It was the War Plans Division that helped to draft "color" plans for the event of war with individual nations (as ORANGE, for war with Japan), and it was also planned that the staff of the War Plans Division would provide the nucleus for any new wartime General Headquarters established to direct operations. The General Staff divisions assisted the Chief of Staff in his supervision of the military branches of the War Department and of the field forces. The principal organizational change thereafter in the 1920's came in 1926 with the establishment of the Air Corps as an equal combat arm and with provision for its enlargement and modernization.

The field forces in the continental United States were put under the command and administration of nine corps areas approximately equal in population, and those overseas in Panama, Hawaii, and the Philippines under departments




with similar authority. The division rather than the regiment became the basic Army unit, especially in mobilization planning, and each corps area was allocated 6 infantry divisions- 1 Regular Army, 2 National Guard, and 3 Reserve. In addition, a cavalry division patrolled the Mexican border, and in Pacific outposts Army mobile units were organized as separate Hawaiian and Philippine Divisions. The defense act had contemplated a higher organization of divisions into corps and armies, but no such tactical organizations existed in fact for many years.


Education for and within the Army between world wars received far greater attention than ever before. This situation reflected the emphasis in the National Defense Act on preparedness in peacetime as well as the increasing complexity of modern war. The United States Military Academy and the Reserve Officers' Training Corps program furnished most of the basic schooling for new officers. Thirty-one special service schools provided branch training. These branch schools trained officers and enlisted men of the civilian components besides those of the Regular Army, and furnished training through extension courses as well as on location. Three general service schools provided the capstone of the Army educational system. The oldest, located at Fort Leavenworth, Kansas, and known after 1928 as the Command and General Staff School, provided officers with the requisite training for divisional command and General Staff positions. In Washington the Army War College and, after 1924, the Army Industrial College trained senior officers of demonstrated ability for the most responsible command and staff positions. In establishing the Industrial College the Army recognized the high importance of logistical training for the conduct of modern warfare.


Regular Army Strength and Support


When the National Defense Act was adopted in June 1920, the Regular Army numbered about 200,000 about two-thirds the maximum strength authorized in the act. In January 1921 Congress directed a reduction in enlisted strength to 175,000, and in June 1921 to 150,000, as soon as possible. A year later Congress limited the active Army to 12,000 commissioned officers and 125,000 enlisted men, not including the 7,000 or so in the Philippine Scouts, and Regular Army strength was stabilized at about this level until 1936. Appropriations for the military expenses of the War Department also became stabilized during this same period, amounting to about $300 million a year. This was about half of what a full implementation of the National Defense Act had been estimated to cost. The United States during these years spent rather less on its




Army than on its Navy, in line with the national policy of depending on the Navy as the first line of defense. War Department officials, especially in the early 1920's, repeatedly expressed alarm over the failure of Congress to appropriate enough money to carry out the terms of the National Defense Act. They believed that it was essential for minimum defense needs to have a Regular Army with an enlisted strength of 150,000 or (after the Air Corps Act of 1926) of 165,000. As Chief of Staff Douglas MacArthur pointed out in 1933, the United States ranked seventeenth among the nations in active Army strength; but foreign observers rated its newly equipped Army Air Corps second or third in actual power.


In equipment the Air Corps offered a marked contrast to the rest of the Army. For almost two decades ground units had to get along as best they could with weapons left over from World War I. The Army was well aware that these old weapons were becoming increasingly obsolete, and that new ones were needed. For example, General MacArthur in 1933 described the Army's tanks (except for a dozen experimental models) as completely useless for employment against any modern unit on the battlefield. Although handicapped by very small appropriations for research and development, Army arsenals and laboratories worked continuously during the 1920's and 1930's to devise new items of equipment and to improve old ones. Service boards, links between branch schools and headquarters, tested pilot models and determined the doctrine for their employment so that it could be incorporated in training manuals. But not much new equipment was forthcoming for ground units in the field until Army appropriations began to rise in 1936.


For a number of years only about one fourth of the officers and one-half of the enlisted men of the Regular Army were available for assignment to tactical units in the continental United States. Many units existed only on paper; almost all had only skeletonized strength. Instead of nine infantry divisions, there were actually three. In May 1927 one of these divisions, a cavalry brigade, and 200 planes participated in a combined arms maneuver in Texas, but for the most part Regular units had to train as battalions or companies. The continued dispersion of skeletonized divisions, brigades, and regiments among a large number of posts, many of them relics of the Indian wars, was a serious hindrance to the training of Regulars, although helpful in training the civilian components. Efforts to abandon small posts continued to meet with stubborn opposition from local interests and their elected representatives in Congress. In the infantry, for example, in 1932 the 24 regiments available in the United States for field service were spread among 45 posts, with a battalion or less at 34. Most of the organic transportation of these units was of World War I vintage, and the Army did




not have the money to concentrate them for training by other means. Nor were there large posts in which they could be housed. The best training of larger units occurred overseas in the fairly sizable garrisons maintained by the Army in Hawaii, the Philippines, and Panama. In the early 1930's the great depression had the immediate effect of cuts in appropriations and pay that further reduced the readiness of Army units for military service.


Civilian Components


One of the major purposes of the National Defense Act had been to promote the integration of the Regular Army and the civilian components by establishing uniformity in training and professional standards. While in practice this purpose fell considerably short of full realization, nevertheless the new Army system saw an unprecedented amount of civilian military training. This training brought the Regular out of his traditional isolation from the civilian community, and it acquainted large numbers of civilians with the problems and views of the professional soldier. All together, the civilian components and the groups in training that contributed to their ranks had an average strength of about 400,000 between the wars. The end result of the civilian training program was to be an orderly and effective mobilization of National Guard and Reserve elements into the active Army in 1940 and 1941.

The absorption of the National Guard into the Army during World War I had left the states without any Guard units after the armistice. The act of 1920 contemplated a National Guard of 436,000, but its actual peacetime strength became stabilized at about 180,000. This force relieved the Regular Army of any duty in curbing domestic disturbances within the states from 1921 until 1941, and stood ready for immediate induction into the active Army whenever necessary. The War Department, in addition to supplying Regular officers for instruction and large quantities of surplus World War I materiel for equipment, applied about one-tenth of its military budget to the support of the Guard in the years between wars. Guardsmen engaged in 48 armory drills and 15 days of field training each year. Though not comparable to active Army units in readiness for war, the increasingly federalized Guard was better trained in 1939 than it had been when mobilized for Mexican border duty in 1916. Numerically, the National Guard was the largest component of the Army of the United States between 1922 and 1939.


In addition to the Guard, the civilian community had of course a very large number of trained officers and enlisted men after World War I, which assured the nation of a natural reservoir of manpower for the Army for




a decade or more after the war. Only a very few of these men joined the Enlisted Reserve Corps, but large numbers of officers maintained their commissions in the Officers' Reserve Corps through five-year periods during which they received further training through school and extension courses and in brief tours of active duty. The composition of the Officers' Reserve Corps, which numbered about 100,000 between the wars, gradually changed as its ranks were refilled by men newly commissioned after training in the Reserve Officers' Training Corps (ROTC) or the Citizens' Military Training Camp (CATCH) programs.

The ROTC program began long before the passage of the National Defense Act, in military colleges of which the first was Nourish University, established in 1819, in state land-grant schools set up under the Morrill Act of 1862, and in a number of private colleges and universities. For several decades before World War I the Army detailed annually up to 100 Regular officers as instructors, and supplied equipment, for college military training; but until the defense acts of 1916 and 1920 the program was only loosely associated with the Army's own needs. The new dependence on the civilian components for Army expansion, and the establishment of the Officers' Reserve Corps as a vehicle to retain college men in the Army of the United States after graduation, gave impetus to a greatly enlarged and better regulated ROTC program after 1920. By 1928 there were ROTC units in 325 schools, about 225 of them being senior units enrolling 85,000 students in colleges and universities. Regular Army officers detailed as professors of military science instructed these units, and about 6,ooo men graduating from them were commissioned each year in the Officers' Reserve Corps. This inexpensive program paid rich dividends when the nation again mobilized to meet the threat of war in 1940 and 1941.


The Army's CMTC program, a very modest alternative to the system of universal military training proposed in 1919, provided about 30,000 young volunteers with four weeks of military training in summer camps each year. Those who completed four years of CMTC training became eligible for Reserve commissions, the CMTC thus providing another (though much smaller) source for the rolls of the Officers' Reserve Corps and the National Guard.


Domestic Employment


The most notable domestic use of Regular troops in twenty years of peace happened in the nation's capital in the summer of 1932. Some thousands of "Bonus Marchers" remained in Washington after the adjournment of Congress dashed their hopes for immediate payment of a bonus for military service in




World War I. On July 28, when marshals and police tried to evict one group encamped near the Capitol, a riot with some bloodshed occurred. Thereupon President Herbert C. Hoover called upon the Army to intervene. A force of about 600- cavalrymen and infantrymen with a few tanks-advanced to the scene under the leadership of Chief of Staff MacArthur in person, two other generals, and, among junior officers, two whose names would in due course become much more familiar, Majors Dwight D. Eisenhower and George S. Patton, Jr. The troops cleaned up the situation near the Capitol without firing a shot, and then proceeded with equal efficiency to clear out all of the marchers from the District of Columbia. From a military point of view the Army had performed an unpleasant task in exemplary fashion, and with only a few minor injuries to participants; but the use of military force against civilians, most of them veterans, tarnished the Army's public image and helped to defeat the administration in the forthcoming election.


Aside from the bonus incident, the most conspicuous employment of the Army within the United States during these years of peace was in a variety of nonmilitary tasks that only the Army had the resources and the organization to tackle quickly. In floods and blizzards and hurricanes it was the Army that was first on the spot with cots, blankets, and food. In another direction, Army Engineers expanded their work on rivers and harbors for the improvement of navigation and flood control. For four months in 1934 the Air Corps, on orders from President Franklin D. Roosevelt, took over the carrying of air mail for the Post Office Department with somewhat tragic consequences, since the corps was wholly unprepared for such an undertaking.


The most important and immediately disruptive nonmilitary duty began in 1933, after Congress passed an act that put large numbers of jobless young men into reforestation and other reclamation work. President Roosevelt directed the Army to mobilize these men and thereafter to run their camps without in any way making the Civilian Conservation Corps (CCC) program a military project in disguise. Within seven weeks the Army mobilized 310,000 men into 1,315 camps, a mobilization more rapid and orderly than any in the Army's history. For more than a year the War Department had to keep about 3,000 Regular officers and many noncommissioned officers assigned to this task, and in order to do so the Army had to strip tactical units of their leadership. Unit training was brought to a standstill, and the readiness of units for immediate military employment was almost destroyed. In the second half of 1934 the War Department called a large number of Reserve officers to active duty to replace the Regulars, and, by August 1935, 9,300 Reserve officers (not counted in active Army strength) were serving with the CCC. A good many of them continued




in this service until 1941, but the Army never wanted to insert military training into the program, in part because the CCC camps were so small and so isolated. Despite its initial and serious interference with normal Army operations, in the long run the CCC program had a beneficial effect on military preparedness. It furnished many thousands of Reserve officers with valuable training, and it gave nonmilitary but disciplined training to many hundreds of thousands of young men who were to become soldiers and sailors in World War II.


National and Military Policy


For fifteen years, from 1921 to 1936, the American people, their representatives in Congress, and their Presidents thought that the United States could and should avoid future wars with other major powers, except possibly Japan. They believed the nation could achieve this goal by maintaining a minimum of defensive military strength, avoiding entangling commitments with Old World nations, and yet using American good offices to promote international peace and the limitation of armaments. The United States took the initiative in 1921 in calling a conference in Washington to consider the limitation of armaments. The resulting naval treaty of 1922 temporarily checked a race for naval supremacy. It froze capital ship strengths of the United States, Great Britain, and Japan in a 5-5-3 ratio for a number of years. This ratio and restrictions on new naval base construction assured that neither the United States nor Japan could operate offensively in the Pacific as long as treaty provisions were respected. In effect these provisions also meant that it would be impossible for the United States to defend the Philippines against a Japanese attack. On the other hand, a general agreement among the western nations and Japan to maintain the status quo in the Pacific and in China offered fair assurance against a Japanese war of aggression, but only as long as the western powers did not themselves become embroiled in the European-Atlantic area.


In 1928 the United States and France joined in drafting the Pact of Paris, which renounced war as an instrument of national policy. Thereafter, the United States announced to the world that, if other powers did likewise, it would limit its armed forces to those necessary to maintain internal order and defend national territory against aggression and invasion. In 1931 the chief of the Army's War Plans Division advised the Chief of Staff that the defense of frontiers was precisely the cardinal task for which the Army had been organized, equipped, and trained. There was no real conflict between national policy and the Army's conception of its mission during the 1920's




and early 1930's. But in the Army's opinion the government and the American public, in their antipathy to war, failed to support even minimum needs for national defense.


Across the oceans, the clouds of war began to form again in 1931 when the Japanese seized Manchuria and then defied the diplomatic efforts of the League of Nations and the United States to pry them loose. In 1933 Japan quit the League and a year later announced that it would no longer be bound by the naval limitation treaties after they expired in 1936. In Europe, Adolf Hitler came to power in Germany in 1933, and by 1936 Nazi Germany had denounced the Treaty of Versailles, embarked on rearmament, and occupied the demilitarized Rhineland. Hitler's partner in dictatorship, Italy's Benito Mussolini, began his career of aggression by attacking Ethiopia in 1935. A revolution in Spain in 1936 not only produced a third dictatorship but also an extended war that became a proving ground for World War II. The neutrality acts passed by the Congress between 1935 and 1937 were a direct response to these European developments, and the United States tried to mend its international position in other ways by opening diplomatic relations with Soviet Russia in 1933, by promising eventual independence to the Philippines in 1934, and by liquidating its protectorates in the Caribbean area and pursuing the policy of the Good Neighbor toward Latin America generally.


No quick changes in American military policy followed. But beginning in 1935 the armed forces received substantially larger appropriations that permitted them to improve their readiness for action. Army improvements during the next three years reflected not only the increasingly critical international situation but also the careful planning of the War Department during General Douglas MacArthur's tour as Chief of Staff from 1930 to 1935. His recommendations led to a reorganization of the combat forces and a modest increase in their size, and were accompanied by more realistic planning for using the manpower and industrial might of the United States for war, if that should become necessary.


The Army Strengthened


The central objective of the Chief of Staff's recommendations had been to establish a small hard-hitting force ready for emergency use. In line with this objective the Army wanted to mechanize and motorize its Regular combat units as soon as it could, and to fill their ranks so that they could be trained effectively. The Army also needed new organizations to control training of the larger ground and air units and teams of combined arms in peacetime and to



command them if war came. For these purposes the War Department between 1932 and 1935 created four army headquarters and a General Headquarters Air Force in the continental United States under command of the Chief of Staff. Under these headquarters, beginning in the summer of 1935, Regular and National Guard divisions and other units trained together each year in summer maneuvers and other exercises, including joint exercises with the Navy. In the same year Congress authorized the Regular Army to increase its enlisted strength to the long-sought goal of i6~,ooo. This increase was accompanied during the following years by substantially greater expenditures for equipment and housing, so that by 1938 the Regular Army was considerably stronger and far readier for action than it had been in the early 1930'S. But in the meantime the strength and power of foreign armies had been increasing even more rapidly.


In the slow rebuilding of the 1930's, the Army concentrated on equipping and training its combat units for mobile warfare rather than for the static warfare that had characterized operations on the Western Front in World War I. Through research it managed to acquire some new weapons that promised increased firepower and mobility as soon as equipment could be produced in quantity. In 1936 the Army adopted the Garand semiautomatic rifle to replace the 1903 Springfield, and during the 1930's it perfected the mobile 105-mm. howitzer that became the principal divisional artillery piece of World War II and developed light and medium tanks that were much faster than the lumbering models of World War I. In units, horse power gave way to motor power as rapidly as new vehicles could be acquired. To increase the maneuverability of its principal ground unit, the division, the Army decided after field tests to triangularize the infantry division by reducing the number of its infantry regiments from four to three, and to make it more mobile by using motor transportation only. The planned wartime strength of the new division was to be little more than half the size of its World War I counterpart.


Modern war is so complex and modern armies are so demanding in equipment that industrial mobilization for war must precede the large-scale employment of manpower by at least two years if a war is to be fought effectively. The Army's Industrial Mobilization Plan of 1930 established the basic principles for harnessing the nation's economic strength to war needs, and revisions of this plan to 1939 improved the pattern. Manpower planning culminated in the Protective Mobilization Plan of 1937. Under this plan the first step was to be the induction of the National Guard, to provide with the Regular Army an Initial Protective Force of about 400,000. The Navy and this defensive force would then protect the nation while the Army engaged in an




orderly expansion to planned strengths of one, two, and four million, as necessary. Along with manpower planning there evolved for the first time prior to actual war a definite training plan, which included the location, size, and scheduling for replacement training centers, unit training centers, and schools, detailed unit and individual training programs, and the production of a variety of training manuals. While these plans were to help guide the mobilization that began in the summer of 1940, they had their faults. As it turned out the planners set their sights too low. They assumed a maximum mobilization of World War I dimension, whereas World War II was to call forth more than twice as many men and proportionately an even greater industrial effort for the Army. The plans also assumed until 1939 that mobilization for war would come more or less suddenly, instead of relatively slowly during many months of nominal peace.


The Beginnings of World War II


The German annexation of Austria in March 1938 followed by the Czech crisis in September of the same year awakened the United States and the other democratic nations to the imminence of another great world conflict. The new conflict had already begun in the Far East when Japan had invaded China in 1937. After Germany seized Czechoslovakia in March 1939, war in Europe became inevitable, since Hitler had no intention of stopping with that move and Great Britain and France for their part decided that they must fight rather than yield anything more to Hitler. In August Germany made a deal with the Soviet Union, which provided for a partition of Poland and a Soviet free hand in Finland and the northern Baltic states. Then on September 1, 1939, Germany invaded Poland. When France and Great Britain responded by declaring war on Germany, they embarked on a course that could not lead to victory without aid from the United States. Yet an overwhelming majority of the American people wanted to stay out of the new war if they could, and this sentiment necessarily governed the initial responses of the United States Government and of its armed forces to the perilous international situation.


President Roosevelt and his advisers, being fully aware of the danger, had launched the nation on a limited preparedness campaign at the beginning of 1939. By then the technological improvement of the airplane had introduced a new factor into the military calculations of the United States. The moment was approaching when it would be feasible for a hostile Old World power to




establish air bases in the Western Hemisphere from which the Panama Canal-then the key to American naval defense-or the continental United States itself might be attacked. Such a development would destroy the oceanic security that the American nation had so long enjoyed. The primary emphasis in 1939 was therefore on increasing the striking power of the Army Air Corps. At the same time Army and Navy officers collaborated in drafting the RAINBOW plans that superseded existing color plans and thereafter helped to guide the development and conduct of the American armed forces toward the war. A month after the European war began the President, in formally approving the RAINBOW I plan, changed the avowed national military policy from one of guarding the United States and its possessions only to one of hemisphere defense, and the policy of hemisphere defense was to be the focus of Army plans and actions until the end of 1940.


Immediately after the European war started the President proclaimed a limited national emergency and authorized increases in Regular Army and National Guard enlisted strengths to 227,000 and 235,000, respectively. He also proclaimed American neutrality in the war, but at his urging Congress presently gave indirect support to the western democracies by ending the prohibition on munitions sales to nations at war embodied in the Neutrality Act of 1937. British and French orders for munitions in turn helped to prepare American industry for the large-scale war production that was to come. When the quick destruction of Poland was followed by a lull in the war, the tempo of America s own defense preparations slackened. The Army concentrated on making its Regular force ready for emergency action by providing it with full and modern equipment as quickly as possible, and in April 1940 by engaging 70,000 troops in the first genuine corps and army training maneuvers in American military history. How adequate the Army was depended on the survival of France and Great Britain. The successful German seizure of Denmark and Norway in April 1940 followed by the quick defeat of the Low Countries and France and the grave threat to Great Britain forced the United States in June to adopt a new and greatly enlarged program for defense, for it then looked as if the nation might eventually have to face the aggressors of the Old World almost alone.


The Prewar Mobilization


Under the leadership of Chief of Staff General George C. Marshall and, after July, of Secretary of War Henry L. Stimson, the Army embarked in the summer of 1940 on a large expansion designed to protect the United States and the rest of the Western Hemisphere against any hostile forces that might be




unleashed from the Old World. Army expansion was matched by a naval program designed to give the United States a two-ocean Navy strong enough to deal simultaneously with the Japanese in the Pacific and the naval strength that Germany and its new war partner, Italy, might acquire in the Atlantic if they defeated Great Britain. Both expansion programs had the overwhelming support of the American people, who though still strongly opposed to entering the war were now convinced that the danger to the United States was very real. Congressional appropriations between May and October 1940 reflected this conviction. The Army received more than $8 billion for its needs during the succeeding year-a sum greater than what had been granted for the support of its military activities during the preceding twenty years. The munitions program approved for the Army on June 30, 1940, called for procurement by October 1941 of all items needed to equip and maintain a 1,200,000-man force, including a greatly enlarged and modernized Army Air Corps, and by September the War Department was planning to create an Army of a million and a half as soon as possible.


To fill the ranks of this new Army, Congress on August 27 approved induction of the National Guard into federal service and the calling up of the Organized Reserves. Then it approved the first peacetime draft of untrained civilian manpower in the nation's history, in the Selective Service and Training Act of September 14, 1940. Units of the National Guard, and selectees and the Reserve officers to train them, entered service as rapidly as the Army could construct camps to house them. During the last six months of 1940 the active Army more than doubled in strength, and by mid-1941 it achieved its planned strength of one and a half million officers and men.


A new organization, General Headquarters, took charge of training the Army in July 1940. In the same month the Army established a separate Armored Force, and subsequently Antiaircraft and Tank Destroyer Commands, which, with the Infantry, Field Artillery, Coast Artillery, and Cavalry,




broadened the front of ground combat arms to seven. The existing branch schools and a new Armored Force School concentrated during 1940 and 1941 on improving the fitness of National Guard and Reserve officers for active duty, and in early 1941 the War Department established officer candidate schools to train men selected from the ranks for junior leadership positions. In October 1940 the four armies assumed command of ground units in the continental United States, and thereafter trained them under the supervision of General Headquarters. The corps area commands became administrative and service organizations. Major overseas garrisons were strengthened, and the Army established new commands to supervise the garrisoning of Puerto Rico and Alaska where there had been almost no Regular Army troops for many years. In June 1941 the War Department established the Army Air Forces to train and administer air units in the United States. In July it began the transformation of General Headquarters into an operational post for General Marshall as Commanding General of the Field Forces. By the autumn of 1941 the Army had 27 infantry, 5 armored, and 2 cavalry divisions, 35 air groups, and a host of supporting units in training in the continental United States. But most of these units were still unready for action, in part because the United States had shared so much of its old and new military equipment with the nations that were actively fighting the Axis triumvirate of Germany, Italy, and Japan.


Toward War


On the eve of France's defeat in June 1940 President Roosevelt had directed the transfer or diversion of large stocks of Army World War I weapons, and of ammunition and aircraft, to both France and Great Britain, and after France fell these munitions helped to replace Britain's losses in the evacuation of its expeditionary force from Dunkerque. More aid to Britain was forthcoming in September when the United States agreed to exchange fifty over-age destroyers for offshore Atlantic bases, and the President announced that henceforth production of heavy bombers would be shared equally with the British. An open collaboration with Canada from August 1940 onward led to a strong support of the Canadian war effort, Canada having followed Great Britain into war in September 1939. The foreign aid program culminated in the Lend-Lease Act of March 1941, which swept away the pretense of American neutrality by openly avowing the intention of the United States to become an "arsenal of democracy" against aggression. Prewar foreign aid was nonetheless a measure of self defense; its fundamental purpose was to help contain the military might of the Axis powers until the United States could complete its own protective mobilization.




Thus by early 1941 the focus of American policy had shifted from hemisphere defense to a limited participation in the war. Indeed by then it appeared to Army and Navy leaders and to President Roosevelt that the United States might be drawn into full participation in the not too distant future. Assuming the probability of simultaneous operations in the Pacific and Atlantic, they agreed that Germany was the greater menace and that if the United States did enter the war it ought to concentrate on the defeat of Germany first. This principle was accepted in staff conversations between American and British military representatives in Washington ending on March 29, 1941.


After these conversations the Army and Navy adjusted the most comprehensive of the prewar planning concepts, RAINBOW 5, to accord with American military preparations and actions during the remaining months of 1941 before the Japanese attack. During these months the trend was steadily toward American participation in the war against Germany. In April the President authorized an active naval patrol of the western half of the Atlantic Ocean. In May the United States decided to accept responsibility for the development and operation of military air routes across the North Atlantic via Greenland and across the South Atlantic via Brazil. During May it also appeared to the President and his military advisers that a German drive through Spain and Portugal to northwestern Africa and its adjacent islands might be imminent. This prospect together with German naval activity in the North Atlantic led the President to proclaim an unlimited national emergency, and to direct the Army and Navy to prepare an expeditionary force to be sent to the Azores as a step toward blocking a German advance toward the South Atlantic. Then, in early June, the President learned that Hitler was preparing to attack the Soviet Union, a move that would divert German military power away from the Atlantic, at least for the time being.


The Germans invaded the Soviet Union on June 22, and three days later Army troops landed in Greenland to protect it against German attack and to build air bases for the air ferry route across the North Atlantic. Earlier in June the President had also decided that Americans should relieve British troops guarding Iceland, and the initial contingent of American forces reached there in early July, to be followed by a sizable Army expeditionary force in September. In August the President and British Prime Minister Winston Churchill met in Newfoundland and drafted the Atlantic Charter, which defined the general terms of a just peace for the world. By October the United States Navy was fully engaged in convoy-escort duties in the western reaches of the North Atlantic, and Navy ships, with some assistance from Army aircraft, were joining with British and Canadian forces in warring against German submarines. In Novem-




ber Congress voted to repeal prohibitions against the arming of American merchant vessels and their entry into combat zones, and the stage was set, as Prime Minister Churchill noted on November 9, for "constant fighting in the Atlantic between German and American ships."

Apparently all of the overt American moves in 1941 toward involvement in the war against Germany had solid backing in American public opinion, with only an increasingly small though vociferous minority criticizing the President for the nation's departures from neutrality. But the American people were still not prepared for an open declaration of war.

As the United States moved toward war in the Atlantic area, American policy toward Japan also stiffened. Although the United States wanted to avoid a two-front war, it was not ready to do so by surrendering vital areas or interests to the Japanese as the price of peace. When in late July 1941 the Japanese moved large forces into what became South Vietnam, the United States responded by freezing Japanese assets and cutting off oil shipments to Japan. At the same time the War Department recalled General MacArthur to active duty to command both United States and Philippine Army forces in the Far East and it also decided to send Army reinforcements to the Philippines, including heavy bombers intended to dissuade the Japanese from making any more southward moves. For their part the Japanese, while continuing to negotiate with the United States, tentatively decided in September to embark on a war of conquest in Southeast Asia and the Indies as soon as possible, and to try to immobilize American naval opposition by an opening air strike against the great American naval base of Pearl Harbor in Hawaii. When intensive last-minute negotiations in November failed to produce any accommodation, the Japanese made their decision for war irrevocable.

The Japanese attack of December 7, 1941 on Pearl Harbor and the Philippines at once ended the division of American opinion toward participation in the war, and America went to war with a unanimity of popular support that was unprecedented in the military history of the United States. This was also the first time in its history that the United States had entered a war with a large Army in being and an industrial system partially retooled for war. The Army numbered 1,643,477, and it was ready to defend the Western Hemisphere against invasion. But it was not ready to take part in large-scale operations across the oceans. Many months would pass before the United States could launch even limited offensives.

page updated 27 April 2001

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