War crimes perpetrated by the Soviet Union and its armed forces from 1919 to 1991 include acts committed by the Red Army (later called the Soviet Army) as well as the NKVD, including the NKVD's Internal Troops. In some cases, these acts were committed upon the orders of the Soviet leader Joseph Stalin in pursuance of the early Soviet Government's policy of Red Terror, in other instances they were committed without orders by Soviet troops against prisoners of war or civilians of countries that had been in armed conflict with the USSR, or during partisan warfare.