ABSTRACT
World War Two was unique. It has been the sole war to involve all the major powers: unlike in World War One, China was a serious combatant and Japan played a major role, while the USA was directly involved for much of the conflict and in both the European and the Pacific theatres. Taking the battle to the Axis required naval mastery in both the Atlantic and the Pacific, although the challenge was very different in each. At sea, as in World War One, the Germans were more effective in submarine than surface warfare. Moreover, the German focus on war with the Soviet Union, which broke out on 22 June 1941, directed German priorities. Germany's allies were also defeated and knocked out of the war. The Soviet advance into the Balkans led in 1944 to the overthrow of pro-German governments in Romania, Bulgaria and Hungary, and to the German evacuation of Greece, Albania and Yugoslavia.
