Tanks played a major role in World War II. Although Italy and Japan produced significant numbers of tanks before and during WW2, it is the German tanks which are best known. The early tanks of Germany were technologically inferior to many of their opponent's tanks in the areas of armour and firepower. It was in their tactical employment that German tanks dominated all rivals early in the war. German doctrine stressed the use of combined-arms involving mobile infantry and air support, and, after its surprising success during the execution of Fall Gelb (Battle of France), the tactic of the Blitzkrieg (lightning warfare). This doctrine required the Germans to equip their tanks with radios, which provided unmatched command and control. In contrast, almost all light French tanks lacked radios, essentially because their battle doctrine was based on a more slow-paced, deliberate conformance to planned movements. This required fewer radios at all levels. French tanks generally outclassed German tanks in firepower and armour in the 1940 campaign, but their poor command and control doctrine made these advantages irrelevant to the final outcome.