Role in WW2
Main article: Single-party period of the Republic of Turkey § 1938–1950: İnönü (National Chief)
Turkey was neutral until several months before the end of the war, at which point it joined the Allied powers. Prior to the outbreak of war, Turkey signed a Mutual Aid Pact with France and Britain in 1939. After the German invasion of France, however, Turkey remained neutral, relying on a clause excusing them if military action might bring conflict with the USSR, which, after the division of Poland, Turkey feared. Then, in June 1941, after neighboring Bulgaria joined the Axis and allowed Germany to move troops through to invade Yugoslavia and Greece, Turkey signed a treaty of friendship with Germany.
Turkey was an important producer of chromite, which is a key ingredient in the manufacture of stainless steel and refractory brick, and Germany had limited access to it. The key issue in Turkey's negotiations with both sides was the sale of chromite to Germany or to the Allies. The Allies had access to other sources and mainly bought the chromite in order to preclude its sale to Germany. Turkey halted its sales to Germany in April 1944 and broke off relations in August. Turkey declared war on the Axis powers in February 1945, after the Allies made its invitation to the inaugural meeting of the United Nations (along with the invitations of several other nations) conditional on full belligerency. No Turkish troops ever saw combat.