Infantry, Part I: Regular Army /Between World Wars, 1919-1941

by John K. Mahon and Romana Danysh

• Between World Wars, 1919-1941

• During the two decades between world wars, the infantry underwent startling changes that exceeded any in its previous history. The greatest of these was in speed. In 1919 a prime object had been to secure trucks to replace horses, so that foot soldiers could move toward the battlefield at fifteen to twenty-five miles an hour. In contrast, twenty years later the equivalent object was to use aircraft so that doughboys could hurtle toward fields of battle ten times as fast.

• These twenty years were as contradictory as they were revolutionary. In them, the foot establishment declined steadily for the first seventeen years, and then soared to great heights in the last two.

• During the first of the two decades, the impact of World War I was naturally dominant. Civilian Americans were determined to retrench from the unheard of costs of world war and, while they were at it, to forget warfare altogether. As a result, the authorized strength of the Regular infantry slid from 110,000 in 1920 to 40,331 in 1932. The proportion of foot soldiers to the whole establishment likewise dropped from near 50 percent to slightly less than 25.

• So great a cut in the infantry-it amounted to 63 percent-of course played havoc with the regiments. Of the sixty-five in the Regular service, eighteen were inactivated in 1921 and eight during 1922. None of these were revived until 1940 and after. This heavy pruning left the block of regiments from the 1st through the 31st intact, with scattered numbers thereafter. The 33nd, 34th, 35th, 38th, 42nd, 45th (Philippine Scouts) , 57th (Philippine Scouts) , and 65th (Puerto Rico) Infantry survived, but the 42nd was inactivated in 1927.

• Even after twenty-seven infantry regiments had been inactivated, it was necessary to lop some battalions from those that survived. In consequence, by 1938 there were fourteen regiments out of the thirty-eight with but two battalions apiece. Nor was the whole reduction yet complete. Next, it was necessary to modify the tables of organization so that in peacetime all but two regiments had headquarters detachments instead of companies, while only one had a howitzer company, the rest having howitzer platoons. Also, rifle and machine gun companies contained two instead of three platoons. Thus reduced, they were hard pressed to turn out one war-strength platoon for purposes of training.

• It is apparent from the figures just given that the thinking of Congress and of the people was more isolationist than before World War I. This fact, reflected in the emaciation of the Army, enforced a defensive psychology on the officers in the service. Accordingly, during the 1920's strategic planning was based on the assumption that if a major war came, it would be waged against the United States by some first-class power fighting in the Western Hemisphere.

• The squeeze was aggravated by the expansion of the Air Corps, whose growth could only proceed at the expense of the other arms. By mid-1931 the infantry had already given 2,656 enlisted men to the growing air arm, and was soon to be drawn on for more. It was necessary to inactivate five battalions in 1930 to meet the quota.

• A sharp pinch persisted until 1935, when the government's policy of spending to combat the Great Depression finally reached the Army and resulted, among other things, in an increased appropriation for personnel. This policy was abetted by the troubled state of Europe. At first the growth was slow, so that by 1939 the infantry had risen 17,000 from its 1932 low. That year the overall policy changed. Whereas before 1939 the Army had been recognized as no more than a cadre, afterwards there was official recognition that an army-in-being was needed, and $1,000,000,000 appropriated to implement its creation.

• Beginning in 1940, some of the Regular infantry regiments, inactive for eighteen or nineteen years, were reactivated. That same year, forty regiments of National Guard infantry were inducted into Federal service, and the next year, thirty-six more. Hence, by mid-1941, there were 379,845 infantrymen of all types in service, organized in 136 regiments (including 18 armored) , 32 battalions (15 of them tank) , and 34 separate companies.

• Even this number did not seem adequate to the Chief of Infantry, whose office was created in 1920. He pointed out that combat infantrymen made up less than 25 percent of the whole Army under the expansion plans, as contrasted with 50 percent in the German establishment. Such a proportion, he said, was not justified. It resulted from the fact that certain elements had been brought into the Army which tended to squeeze the infantry out. One of these was the heavy siege elements introduced during World War I for reducing trenches; the other was the armored element brought in afterward for use in distant maneuver. If the high command shared this view, it did not show the fact by altering the ratio of infantry to the whole Army. However, basic doctrine as late as 1939 restated the old principle that infantry was the prime element in combat, and that rifle and bayonet were still the chief weapons.

• The experience of World War I was distilled into one document that cut across every phase of military life. This was the National Defense Act of 1920. It touched the infantry in many ways, but the principal way was in the creation of a Chief of Infantry. For some years agitation to provide the combat arms with chiefs had been growing. As a result of the National Defense Act, the doughboys after 1 July 1920, for the first time in United States history, had a chief who was the peer of the chiefs of the cavalry, coast artillery, field artillery, and of the technical services.

• Another consequence of that comprehensive act was the assignment of tank units to the infantry. Thereafter for twenty years, development of tank materiel and doctrine was a responsibility of the Chief of Infantry. Tank units were known as "infantry (tanks)." A Tank Board and a Tank School were transferred in 1920 from the abolished Tank Corps of World War I, along with a number of tank companies. In 1929 some of these companies were formed into two newly constituted regiments, designated the 1st and 2nd Tank Regiments. In 1932 they were redesignated as the 66th Infantry (Light Tanks) and 67th Infantry (Medium Tanks), respectively. The next year saw the constitution of two additional light tank regiments, the 68th and 69th, which were kept inactive. In 1940 the 69th was disbanded and the other three regiments, together with the former divisional tank companies, were assigned to the new Armored Force.

• Lean as the infantry establishment was between world wars-even with the tanks in it-it nonetheless benefited from more careful planning and study than ever before. A few months prior to the appointment of a Chief, an Infantry Board designed to guide and plan developments in weapons and organization came into being at Fort Benning, Georgia. This body reported to The Adjutant General through the Infantry School. Attached to it was a Department of Experiment whose mission was to subject weapons and equipment to extensive tests. Naturally, when the Chief took office these units became responsible to him.

• The Chief of Infantry, the Infantry School, the Infantry Board, the Department of Experiment, the Tank Board, and the Tank School engaged vigorously in the development of infantry. Their earliest contribution was a complete revision of the tables of organization. In this alteration, made during the twenties, the square division survived, but some of its infantry components were considerably modified. The most extreme change took place in infantry battalions, where one rifle company was eliminated and replaced by a machine gun company. This corrected the confusion of World War I in the use of machine guns by placing heavy machine guns under the control of infantry battalion commanders. Almost as extreme was the reduction of the number of platoons in a rifle company from four to three. Both these changes were in the direction of what was later called "triangularization," although it was not yet accepted as a broad principle.

• Such changes, of course, reduced the firepower actually carried forward by infantrymen in an assault. No one claimed that the heavy machine guns, now organic to a battalion, could keep pace with the attacking doughboy. The reduction stemmed in part from the experience of the recent war which had shown that the number of rifles in a regiment was close to impossible to control. Also, it stemmed from the shrinking quantity of manpower available to the Army. In any case, two types of tables of organization were prepared, one for war, the other for peace. This dualism persisted to the very eve of the next war.

• By the early thirties, improvements in weapons had made it possible for fewer men to deliver the same volume of fire. As an example, experts tinkered with the Browning Automatic Rifle (BAR) in an effort to correct its known weaknesses. By adding a butt plate, a small bipod, and a cyclic rate regulator, they greatly augmented the value of the weapon. The improvements, unfortunately, added five pounds to its weight.

• The automatic rifle remained located within the rifle squad where it had come to rest at the close of the war. In 1930, one more was added provisionally to build up infantry firepower, making two to every squad. This arrangement did not last long but gave place to the older order in which one BAR was in every squad. Not until 1 February 1940 was this organization disturbed. Then, at the express request of the Chief of Infantry, who thought the added weight of the gun had put it out of the class of arms to be carried forward by riflemen, the BAR was removed from the rifle squad and put into a separate squad within the rifle platoon.

• The BAR was not regarded as the decisive element in infantry firepower. American emphasis remained on the individual doughboy's shoulder arm. Accordingly, in the effort to substitute firepower for manpower there was a continuous search for an efficient self-loading rifle. Experiments by the Infantry Board soon made it clear that a semiautomatic rifle could increase the infantryman's rate of fire from ten or fifteen aimed shots to twenty or thirty per minute. What is more, the rounds could be better aimed because the marksman did not have to unsettle his aim to operate a bolt.

• The Garand rifle, designated Ml, was selected for development. By 1934 there were eighty Ml's on hand, and by the fall of 1938 they were replacing the 1903 Springfield at the rate of 150 per week. Even so, the new rifle did not replace the old until after war had begun. Since the new rifle could deliver twice the fire of its predecessor, it made possible reductions in other weapons. For example, the total of automatic rifles in a regiment dropped from 189 to 81 in 1943. Although the figure subsequently rose, it never again, not even in war, attained the earlier level.

• Likewise, the M1 influenced fire tactics. Notwithstanding that arms like it were known and used in Europe, they did not affect doctrine the same way as in this country. On the continent, firepower was increased principally by augmenting the number of light machine guns, while in the United States the increase came principally from the faster shooting shoulder arm of the individual rifleman. Thus in Europe, fire superiority depended on a gun served by a crew; in the United States it depended on the individual doughboy and his weapon. It is not implied that the American Army slighted light machine guns. On the contrary, the World War I weaknesses of the BAR, together with its limitations, provoked much research to develop a suitable light machine gun. During the twenties and part of the thirties, the BAR was included in infantry armament only as a substitute for a hypothetical light machine gun which experts expected to be developed. Finally, in February 1940, at the suggestion of the Chief of Infantry, a true light machine gun appeared for the first time in the table of equipment. As this weapon was in very short supply, the improved BAR was made the official substitute. As a result, for the time being, BAR's were found in two different portions of an infantry company. They were standard armament in each rifle squad, and in addition, they were substitute armament in what was called the weapons platoon.

• This weapons platoon (new in 1939) was part of a trend to integrate all necessary weapons except artillery and tanks into the basic tactical unit, the battalion. That trend .made every element of an infantry battalion, even the squad, a more complex organization than before, and at the same time vastly increased its firepower. The heightened complexity, of course, brought with it the need for better communications, better training, and above all better leadership.

• The improvements in portable weapons were important, but by no means as sharp a break with the past as the development of the arms that have come to be known as heavy weapons. These were first used during World War I; hence there was much to be done toward improving them and adjusting organization to use them most efficiently.

• The first change to accommodate organization to the heavy weapons was the creation in 1920 of a howitzer company in each regiment to utilize the Stokes mortars and one-pounder cannon. Since the Regular infantry had not enough men to maintain the new howitzer companies, they were reduced to platoons. The National Guard, however, continued to support full companies. Into the howitzer unit, whether platoon or company, from time to time went various heavy infantry weapons devised between the wars. Among these were 81-mm. mortars, which were first used in very limited quantities in 1932; the various types of 37-mm. cannon, which replaced the one-pounder cannon; and .50-caliber machine guns.

• The howitzer company was always more of an aspiration than a reality. Its name gave no clue to the weapons in it. Rather the name indicated the desire for a howitzer to accompany the infantry, a need which combat in World War I had seemed to reveal. In the years between wars no adequate accompanying cannon was developed. Finally, in the sweeping revision of 1939, the howitzer company was eliminated and its 37-mm. cannon put into a new antitank company in each regiment.

• In the same broad revision, the old machine gun companies of infantry battalions were reorganized to become heavy weapons companies. They absorbed the .30-caliber heavy machine guns of the older company and, in addition, acquired two 81-mm. mortars and two .50-caliber machine guns. The creation of the battalion heavy weapons company was part of the trend to include all weapons within a battalion that it would need to use whether attacking or defending. The process added greatly to the firepower of a battalion.

• All the changes in organization and all the vigorous experiment with arms did not actually produce the weapons that were needed for training. Everything was in very short supply. In consequence, as late as 1941 mortar crews went through maneuvers with stove pipes and the crews of light machine guns set up and aimed broomsticks. These harsh facts caused the Chief of Infantry to state on the eve of war that a consciousness of obsolescence in all their arms had seriously damaged the morale of American infantrymen.

• After 1939, battalion heavy weapons companies, regimental antitank companies, and weapons platoons within rifle companies were largely manned by soldiers, who required some side arm other than the heavy Garand rifle. The ideal weapon for the crews of mortars, machine guns, and antitank guns had to be light, have a rapid rate of fire, and yet have greater range and accuracy than a pistol. As a result, the number of pistols authorized declined steadily, while new light side arms multiplied. One of the latter was the carbine, which came into general use in 1942. Another was the submachine gun, which had been used experimentally since 1922.

• World War I had displayed two very pressing needs in warfare. One was for protection from devastating fires, the other for greater mobility. When applied to infantry, the two were contradictory, for the more protection the infantryman had, the heavier and slower he tended to become. After the war, tanks were made part of the infantry. They offered foot soldiers some added mobility and some protection. Accordingly, infantry doctrine took tanks into account, and the American infantry division included a company of light tanks in its organic structure. Indeed, in the basic theory expressed in the Field Service Regulations of 1939, armor was given the primary mission of helping the infantry advance. This being so, one can understand why the Chief of Infantry strongly protested when in July 1940 armor was removed from infantry control. As of 1939, tanks dropped out of infantry divisions, and never re-entered organically until after World War II.

• Mobility was slowly increased in the infantry by the use of trucks. Hardly anyone doubted the value of motor vehicles to speed the movement of foot troops, but lack of funds restricted their use. Beginning in 1922 trucks replaced animals in the field and combat trains of four regiments. Later, other regiments received vehicles for the same purpose. By 1932, twelve were partly motorized. The trucks, however, were mostly worn-out leftovers from World War I.

• It was the priming of the economic pump that finally secured some new vehicles for the infantry. In 1936 Congress authorized the purchase of 1,000 trucks and cars. With these, division and regimental headquarters could have autos, and six regiments could motorize their machine gun companies and howitzer and communications platoons.

• Experiments with organization, motorization, weapons, and equipment were continuous in the decades between the wars, but the culminating experiments took place in 1937, 1938, and 1939. These were brought about by a growing belief among military leaders that the square divisional organization of World War I was too large and too unwieldy. Experts did not expect the static warfare of 1915-17 to recur; hence they no longer saw the need for the great power of penetration possessed by the square division. On the contrary, mobility was rising in importance, and it was hampered by large numbers. Regimental organization was in such confusion that there were five different types in the United States, while no two regiments serving overseas were alike. This was another consideration which prompted attempts to reorganize.

• The object sought was an infantry division that was smaller and faster than the old one but with as much firepower. To obtain it the infantry establishment, from squad up to division, was given the most thorough examination it had ever received. Not everyone engaged in the examination agreed as to the means to the end. Most accepted three infantry regiments to a division, but differed as to their composition. The Chief of Infantry, for example, proposed four instead of three platoons to a rifle company, and a fourth rifle company in each battalion.

• In any case, in 1937 the 2nd Division was formed into a provisional unit to test the various proposals. For several months it tried out the suggested arrangements in the field. The trials were remarkably thorough, although they were handicapped by shortages of weapons and vehicles. For example, no light mortars were available, while only one regiment could be completely equipped with the M1 rifle. There were not enough .50-caliber machine guns and, of course, no light machine guns at all.

• What emerged from the tests was a full new set of tables of organization which became effective during 1939. The new tables were built upon a triangular basis in which elements within an infantry division, from squads up to regiments, were associated by three's. Two levels of organization in the infantry were eliminated altogether, one large and the other small. These were brigades and sections. Triangularization made possible a simple and effective tactical doctrine, but some experts belittled this aspect. They said that the real reform in 1939 did not come from embracing a triangular organization but from the modernization of weapons that accompanied it.

• The cornerstone of all infantry organization, the squad, was enlarged for wartime from eight men to twelve. This was done in spite of the evidence produced in the field tests that seven or eight men were all one corporal could hope to control in battle. The Chief of Infantry strongly urged the increase. The command weakness of so large a squad was corrected late in 1940 when the leader was made a sergeant and his assistant a corporal. With two noncoms in charge of it, the infantry squad would remain at twelve throughout the coming war.

• One fact that made smaller divisions feasible was the fixed principle that divisions would usually operate as parts of larger units, that is, corps and armies. As parts, they could draw upon pools established in the big elements whenever they needed more men or more equipment than was normal. In other words, they would retain as organic only the units they needed for normal operations. The War Department called this arrangement "pooling," and put it into effect wherever practicable. The new grouping of heavy and crew-served weapons into battalion heavy weapons companies was a practical application of pooling. Also, the antitank weapons of regiments were pooled in antitank companies, and light machine guns and mortars in the weapons platoons of rifle companies.

• The regiment adopted in 1939 was much smaller than before, containing but 2,542 men. According to the Chief of Infantry, such a regiment was too small by several hundred for effective combat action, and he vehemently protested. This protests resulted in new tables of organization the next year which raised the strength of a regiment by 907 men, and battalion and company proportionately.

• The new triangular organization was put into effect in the Regular Army during 1939. Within the National Guard, however, the square organization, somewhat modified, persisted even after many units had entered Federal service in 1940.

• All in all, the Chief of Infantry contended, and rightly, that in the years from 1937 to 1941 American infantry had undergone a real revolution. The foot establishment had been arranged along lines that were more carefully tested than ever before in peacetime. As for weapons, they were turned over completely, except for the .30-caliber heavy machine gun. The 60-mm. mortar (first adopted as standard in 1937, but remaining scarce) had replaced the old Stokes and its successors, while the heavier 81-mm. mortar had been introduced. A light machine gun had actually been adopted, and the BAR was so much improved as to be virtually made over. Finally, the 1903 Springfield shoulder rifle had yielded its place to the semi-automatic M1. In addition, new small arms such as carbines and submachine guns had entered infantry armament, together with a larger machine gun, the .50-caliber.

• As a result of the revolution, the Chief of Infantry believed his branch to be organized on sound principles. The battalion, he said, was now a complete combat unit which contained within itself all elements, save armor and artillery, necessary to attack or to defend. Its weapons could be employed in direct or indirect fire and for high angle missions, or, if needed, for those requiring flat trajectories and high muzzle velocity. It was no longer dependent on attachments from regimental units for its firepower, needing to draw on pools only under unusual conditions.

• Moreover, the elements of infantry were arranged according to mobility. A squad had the standard mobility of a rifleman; a platoon that of a BAR man. Platoons contained no crew-served weapons, and none requiring continuous resupply of ammunition. No weapon in the platoon served as a focus for hostile fire. At company level, the heaviest weapons (light machine guns and 60-mm. mortars) could be carried by hand; even a battalion contained no guns which could not be manhandled for several hundred yards. All weapons needing prime movers were placed in regimental units.

Notes

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