War Production. Sometimes called the "Battle of Production," the struggle by the warring powers to outproduce each other was intense. In most countries, production of consumer products was ended or greatly reduced, and machinery, resources, and labor were used to manufacture war goods. The United States was by far the most, productive nation in the war, in large part because its already huge industrial capacity was never touched by the destruction of war.

The Soviet Union was able to move many of its industrial plants east of the Ural Mountains, out of the reach of German bombers, and produce huge quantities of arms. Germany did not fully mobilize its industry for war until about 1941. Despite being hampered by air attacks and the scarcity of raw materials, German industry remained productive until the last months of the war.

An important part of each belligerent's war effort was the attempt to destroy the enemy's ability to produce. Aerial bombardment and naval blockades were the means most commonly employed. Germany and Japan were both heavily dependent on imported resources, such as oil, rubber, and iron, and each was the target of blockades intended to cut off these vital supplies. Germany attempted, with somewhat less success, to blockade Great Britain and the Soviet Union, which were also dependent on imported goods.