The Mongolian People's Republic (Mongolian: , ; Bgd Nairamdakh Mongol Ard Uls, BNMAU; [but nermdx m ar()t u()s]) was a socialist state which existed from 1921 to 1992, located in the historical region of Outer Mongolia in East Asia. It was ruled by the Mongolian People's Revolutionary Party and maintained close links with the Soviet Union throughout its history.Geographically, it was bordered by China to its south and the Soviet Union (via the Russian SFSR) to its north. Until 1944, it also bordered the Tuvan People's Republic, a Soviet satellite state recognized only by Mongolia and the Soviet Union.

The Workers' and Peasants' Red Army, often shortened to the Red Army, was the army and air force of the Russian Soviet Federative Socialist Republic and, after 1922, the Union of Soviet Socialist Republics. The army was established in January 1918. The Bolsheviks raised an army to oppose the military confederations (especially the various groups collectively known as the White Army) of their adversaries during the Russian Civil War. Starting in February 1946, the Red Army, along with the Soviet Navy, embodied the main component of the Soviet Armed Forces; taking the official name of "Soviet Army", until its dissolution in 1991.

The Red Army provided the largest land force in the Allied victory in the European theatre of World War II, and its invasion of Manchuria assisted the unconditional surrender of Imperial Japan. During operations on the Eastern Front, it accounted for 75–80% of casualties the Wehrmacht and Waffen-SS suffered during the war and ultimately captured the Nazi German capital, Berlin.