The powerful forts of the Maginot Line would defend the French frontier with Germany. The majority of the French Army's best and most mobile units along with the British Expeditionary Force, would be sent into central Belgium to link up with Belgian Army to fight the battle with Germany on Belgian soil. The French High Command considered that the wooded and hilly terrain of the Ardennes in southern Belgium made it impassable for large enemy formations, and guarded this seemingly quiet sector with the Second and Ninth Armies, both weak and low-grade formations. This deployment would later play straight into Germany's hands. .
French doctrine implied that the three divisions in the Cavalry Corps, each with 174 tanks, were to fan out as a covering force for the main Allied armies designated to move to the support of Holland and Belgium in the event of a German invasion. Having made contact, they were then to withdraw under pressure to the Allied line of defense and enter reserve, poised to counter-attack enemy penetrations prior to rolling him back in a grand counter-offensive. Dispersed across a wide front, the tanks, infantry and guns of these formations were to be committed in small packets or as individuals. Opportunities for mutual cooperation were further diminished by poor communication systems. Even if they could have concentrated against the German armor, each tank commander had numerous jobs other than directing his crew. The German's, however, had two or three man turret crews so the commander could concentrate on command function and leave the shooting to his gunner. The French army did attempt to form divisions for concentrated offensive operations, but not until the fall of Poland. However, only three divisions would be formed before the Germans struck; none had yet trained to the techniques demanded by fluid operations; and every tank suffered from the same gunnery limitations.
