The U.S. participated in the allied military intervention against the Bolsheviks during the Russian Civil War since August 1918, operating in the Russian Far East. Following the Bolsheviks′ victory in the Civil War and the establishment of the Soviet Union (USSR) at the end of 1922, the U.S., while developing trade and economic ties, was the last major world power that continued to refuse to formally recognize the Soviet government. The United States and the USSR established diplomatic relations in November 1933.