(March 16, 1921), pact concluded at Moscow between the nationalist government of Turkey and the Soviet Union (Union of Soviet Socialist Republics) that fixed Turkey's northeastern frontier and established friendly relations between the two nations.

With the advent of the Russian Revolution (October 1917), Russia withdrew from World War I and ceased hostilities against the Ottoman Empire. The new Soviet regime found itself allied against the West with the Turkish nationalists, who were fighting against both Western domination and the Ottoman government that had capitulated to the Western Allies. Diplomatic relations between the nationalists and the Soviets began in August 1920 and led to the Treaty of Moscow, which settled border disputes by giving Kars and Ardahan to Turkey and Batumi to Russia and by which the Soviets recognized the nationalist leadership under Mustafa Kemal (later styled Kemal Atatürk (Atatürk, Kemal)) as the only government in Turkey. As a result of the treaty, the Soviets supplied the nationalists with weapons and ammunition, which the Turks used successfully in a war against Greece in 1921–22.