Despite the shortage of medium tanks, the military hierarchy had no intention to form the first armored division with tanks other than medium tanks. At the Riom trial, Col. Jean Perré stated that Gamelin anticipated formation of the first armored division in October 1940. Only then would sufficient “heavy” tanks be available. Due to matériel limitations and in accordance with the recommendations of General Martin’s study group, however, the new division would contain only four tank battalions, rather than the six originally included in the 1936 rearmament program. By continuing to link the formation of the first armored division to the presence of sufficient B-model tanks for equipping the entire division, the High Command delayed the formation of the first armored division at a time the French army badly needed such units for experimentation and training. Only the German demonstration in Poland of the use of armored divisions finally overcame the reluctance of the High Command to form an armored division without the perfectly designed and heavily armored medium tanks, which were now being called “heavy” tanks. The rapid collapse of Poland provided a sense of urgency to the creation of armored divisions that had not previously existed.
When the first two armored divisions were formed in January 1940, each had a demi-brigade of light tanks, another of heavy tanks, and a final one of motorized infantry consisting of only one or two battalions. Each demi-brigade of tanks had two battalions. One demi-brigade had in each battalion forty-five H-39 tanks, an improved version of the H-35 tank with greater speed and a more powerful 37mm cannon. The other two battalions had thirty-three B-model tanks, giving each division a total of 156 tanks. Meanwhile, France continued to wait for more B-model tanks; the High Command would not divert infantry-support tanks to the formation of additional armored divisions, and production of the B-model tanks remained agonizingly slow. Additionally, the hastily formed divisions suffered from a lack of equipment, such as tank retrievers, road transporters, and antitank guns.
The Provisional Notice on the Use of Units of the Armored Division, which had been written by General Martin and his study group, was published in February 1939. The ideas contained within the manual were a direct extension of the ideas appearing in the 1932 and 1933 field tests and developed or modified in subsequent years. The manual concentrated on the employment of the armored division to assist the maneuver of a larger unit, which was obviously an infantry unit. It also discussed the actual employment of the division as if it were simply a much larger grouping of mass-maneuver tanks. The French still intended to employ the large tank units to increase the offensive power and assist the maneuver of the infantry, which remained the decisive arm.
The manual also included a concept for successive objectives, but the bounds were increased to three to four kilometers because of the great size of the division. The tanks would be “habitually” organized into two echelons with two or three battalions in the first echelon and one or two battalions in the second echelon. While the first echelon fought its way to the next objective, the second echelon protected its flanks or reduced centers of enemy resistance bypassed by the first echelon.
The manual did make a number of improvements in the employment of the artillery. For example, the manual noted that the tanks would not necessarily halt their attack to permit the displacement of the artillery. The manual also noted that the commander centralized the artillery when it was necessary, but had to decentralize the artillery to ensure a rapid exploitation. To give greater flexibility to artillery coverage, the manual proposed having ground observers in armored vehicles following the attacking tanks. If possible, the observer placed himself on the crest of a hill overlooking the attack and directed the supporting artillery fire from there until the attacking tanks reached the next crest. If the terrain were woody or visibility limited, the observer followed the tanks closely. But with the limited artillery (two battalions) in the proposed tank division, most fire support came from the corps or army being assisted by the tank division. Thus, while there were some improvements in the division artillery’s responsiveness, most fire support remained centralized and actually outside the control of the division commander.
In short, the 1939 manual on the employment of the tank division made that large unit perform within the constraints of the methodical battle. The successive objectives, the tight control, the employment of echelons or waves of tanks, and the dependence on artillery support provided by other units ensured that the division operated in essentially the same fashion as a battalion of mass maneuver tanks. If there were a difference, it was mainly in scale. The frontage and firepower of the division were much greater, and the anticipated depth of the attack was deeper. Similarly, the division’s major purpose was to assist the maneuver of an infantry corps or army, rather than of a regiment or division, but General Martin and his study did not foresee the creation of a mobile battlefield. Where a new doctrine was possible, the French were content to make incremental changes in the methods which had slowly evolved through the 1930s.
In contrast with the careful employment envisaged for the armored division, the French army considered the light mechanized division of the cavalry eminently suited for more mobile operations. Although the organization of the division changed during the 1930s, by May-June 1940 the first and second light mechanized divisions had a reconnaissance regiment equipped with forty-five Panhard armored cars and a brigade consisting of a regiment of truck-borne infantrymen and a squadron of sixty light reconnaissance tanks. They also had a combat brigade consisting of two regiments with each regiment having eighty-seven SOMUA S-35 or eighty-seven H-35 or H-39 tanks. Though earlier concepts were not as forward thinking, the light mechanized divisions by 1939–1940 were designed to fulfill the traditional roles of cavalry units on the battlefield and also to be able to accomplish, with appropriate reinforcement, missions usually assigned to infantry or armored divisions. Ironically, the wartime doctrine for the employment of the mechanized cavalry units, except for the emphasis on cavalry-type operations, closely resembled the eventual doctrine of most Western powers for the employment of mechanized units during the battles of World War II. The important problem becomes one of determining why the doctrine for the employment of the light mechanized division was so much farther advanced than the doctrine for the employment of the armored division by 1939–1940.
Efforts for the mechanization and motorization of the cavalry began in the late 1920s—often to the disgust of the cavalrymen, who remained attached to their horses—but they did not accelerate rapidly until after 1930. When a new regulation on the cavalry appeared in 1930, it emphasized the evolving nature of cavalry tactics but reflected very little that was fundamentally new. Following organizational and weaponry changes, the manual explained, the cavalry was particularly suited for “rapid engagement on extended fronts,” for “abrupt and violent” action by fire, and for the conduct of the exploitation. The cavalry division could also be employed on security or reconnaissance missions, and as a “highly mobile reserve of fire.” While the division could be employed in the offensive, it was best suited for employment in weakly defended intervals, on exposed flanks, or against unprepared defenders. The regulation emphasized that an attack by a cavalry division was different from that by an infantry division, for a cavalry division attack was based on “the exploitation of the effect of surprise,” while an infantry attack was based on a “succession of efforts.” Defensive combat, however, was like that of the infantry division; it was based on the “establishment of barrages of continuous fire.” As for the effect of firepower, the regulation strongly emphasized that fire and movement were “intimately bound together.” There was no inordinate emphasis placed on firepower, since the cavalry had depended on mobility as one of its distinct characteristics for centuries.
Although the 1930 regulations concentrated on the horse cavalry, it also mentioned the employment of tracked vehicles, trucks, and motorcycles. It did not anticipate, however, the appearance of large, mechanized cavalry units. Nonetheless, the 1930 regulations provided a foundation on which future mechanized doctrine and units could be built. Through its emphasis on mobility, the rapid use of firepower, surprise, and immediate exploitation, the cavalry doctrine provided a natural framework for mechanization efforts. This contrasts sharply with infantry and artillery doctrine, which emphasized mobility and flexibility much less.
While General Weygand was chief of the General Staff, from January 1930 until February 1931, and vice-president of the Superior Council of War, from February 1931 until January 1935, the French army made major advances in the mechanization of its cavalry formations. Weygand’s role in the modernization of French cavalry was of crucial importance. In 1933, he followed the suggestion of Gen. J.A.L.R. Flavigny, the director of the Department of Cavalry, to create the light mechanized division, and in June 1934 he began studies on the development of a cavalry tank. This tank was eventually to be the SOMUA S-35 tank, probably the best tank on the battlefield in May–June 1940 because of its great mobility, superior weapons, and excellent armor protection. The new tank weighed 19.5 tons, had a maximum speed of forty-five kilometers per hour, had a maximum armor plating thickness of 55mm, and was armed with a 47mm cannon and a machine gun. Unlike the B-model tank, it never suffered complex development problems. In 1935, the cavalry ordered a hundred of the S-35s before the tank completed required army testing. In contrast to the delayed formation of large units of B-model tanks, the cavalry formed the light mechanized division before the arrival of the first S-35 tanks. The eagerness of the cavalry enthusiasts to form large mechanized units differed sharply from that of the infantry officers who were charged with developing tank units.
With the appearance of the light mechanized division and the possibility of stronger tanks, a new cavalry regulation, entitled Provisional Notice on the Employment of Mechanized and Motorized Units of the Cavalry, appeared in 1935. The new regulation did not replace the 1930 regulation, but it closely defined the missions of the light mechanized division, including the conduct of security and reconnaissance operations, the exploitation of a breach of enemy lines, and the sealing of a breach in friendly lines by occupying a defensive position or by counterattacking. Although the division could be employed in the offensive, it was most suited, according to the regulation, for movements to contact and for operations after a front had been ruptured by other units. When the regulations described how an attack should be conducted with the light mechanized division, it emphasized that such an attack should be closely supported by the artillery and infantry and should not be conducted against an enemy in a strongly held position. In 1935, General Flavigny, commander of the first light mechanized division, explained that the division was best suited for offensive operations on an enemy’s flank or in the exploitation of a breakthrough.
Even though the mechanized cavalry divisions could be used in an offensive or defensive manner, French doctrine in the mid-1930s still placed a greater stress on traditional cavalry missions of reconnaissance and security. At the War College, in 1935–1936, an instructor noted that the mechanized division could accomplish the same sort of missions for a large motorized unit that a nonmechanized cavalry unit could accomplish for the “normal” large units. The doctrine for employing the light mechanized division thus did not differ greatly from the doctrine for employing other cavalry divisions. The major difference was the recognition that the capacity of the mechanized unit for movement over long distances was greater than that for the horse-cavalry units. The 1936 instructions on the tactical employment of large units succinctly summarized the capabilities of the light mechanized division:
Equipped for the distant search of intelligence, capable of assuring its own security, it is able to fulfill, with necessary reinforcements, all the missions assigned to large units of cavalry; it is able in particular to assure the reconnaissance and the security indispensable to large motorized units.
In the late 1930s, the French continued to study the proper employment of the light mechanized division, and by 1939 they placed greater emphasis than before on the offensive capability of the division. The change was not an immediate one. In 1938, several lectures on the new division were presented at the War College and the Center of Higher Military Studies. The major theme of these lectures was the capability of the mechanized cavalry division to perform traditional cavalry missions. One lecturer especially emphasized the much greater mobility of the mechanized division over the horse-equipped division. While the lecturers did not foresee the division conducting a static, position defense, they did emphasize the offensive capability of the mechanized unit. They qualified this assertion, however, by adding that the division should be employed before the enemy strongly reinforced his defenses. In 1938, General Flavigny emphasized the offensive capability of the light mechanized division. He pointed out that the division was equipped with the SOMUA S-35 tank, which was better than the D-model tank, and that it was also equipped with the H-35, the equal of the R-35 tank. The presence of these two tanks enabled the division to conduct frontal attacks, as well as attacks on an enemy’s flanks. Flavigny emphasized that such missions should be given to the mechanized cavalry divisions only in “exceptional” circumstances. Since many of the subordinate units with the division were not suited for the offensive, the best mission for the mechanized division was one in which all elements could participate—obviously the traditional cavalry missions of reconnaissance, security, and exploitation.