In 1939, Iran proclaimed its neutrality. As experienced during World War I, Iranian opinion had pro-German sympathies, above all as a reaction to British hegemony. But more so than in 1914, its neutrality was unacceptable to the belligerent nations because of its strategic position and the importance of its oil. The Soviets and British agreed to occupy it, in the first place to stop the German advance toward the Caucasus and, secondly, to supply the Soviet Union with food and arms.