Watch Online Free on Watchseries. The stalemate of trench warfare in World War I was finally broken by the tank and self-propelled gun, and Germany capitulated. These weapons came fully into their own in World War II, and combined with the tactics of blitzkrieg, gave Germany early supremacy. Ground support aircraft such as Stuka dive-bombers were used to devastating effect. The Soviet response to this combination was the T-34 tank whose 76 or 85mm gun could fire high explosive shells as well as armor piercing rounds.