Belgium, which had refused to let French and British forces deploy on its soil, belatedly allows them after the Germans invade it. After three weeks of fighting, Belgium is overrun and King Leopold, who was never enthusiastic about waging the war, surrenders. The Germans then invade northern France, bypassing the Maginot Line by way of the Ardennes. Although the French are repeatedly driven back, the force of the German Blitzkrieg is not as overwhelming if the German arms industry had received another year to produce more advanced tanks. With the war launched in 1938, the Germans must rely heavily on the Panzer I, a light tank that was intended originally for training. Also, with an active Eastern Front against the Soviets, the Wehrmacht is unable to concentrate all of its forces in the west.