The Kalmyk deportations of 1943, codename Operation Ulussy, was the deportation of most people of the Kalmyk nationality in the Soviet Union (USSR), and Russian women married to Kalmyks, but excepting Kalmyk women married to another nationality. The decision was made in December 1943, when NKVD agents entered the homes of Kalmyks, or registered the names of those absent for deportation later, and packed them into cargo wagons and transported to various locations in Siberia: Altai Krai, Krasnoyarsk Krai, Omsk Oblast, and Novosibirsk Oblast. Around half of those Kalmyk people deported to Siberia died before being allowed to return home in 1957.
Under the USSR, the Kalmyks were forcibly settled from the nomadic lifestyle and Kalmyk Buddhist monks and nuns were persecuted. Thus, during the Nazi invasion and occupation of Kalmykia in 1942, German forces found volunteers among the Kalmyks for the Kalmykian Voluntary Cavalry Corps, which killed many Soviet partisans. The occupying Germans and their puppet regime also destroyed much of the agriculture of the region and executed close to 20,000 people in Kalmykia, including 100 Jews. After the war, Kalmyks were one of the "punished peoples" who were officially accused of military collaborationism with the Nazi army against the Red Army during World War II, of providing the Germans with livestock, of dismantling kolkhozes and sovkhozes with the Germans, of terrorizing the population, etc. At the same time, the Kalmyk Autonomous Republic (ASSR) was abolished, its territory given to neighboring republics. A new decree allowed Kalmyks to return and reestablished the ASSR in 1956.
On November 14, 1989 the Supreme Council of the Soviet Union (the supreme legislative body) declared that deportation of kalmyks and other soviet minorities was a "barbaric action of the Stalin's regime" and a very serious crime.
Under the Law of the Russian Federation of April 26, 1991 "On Rehabilitation of Exiled Peoples" repressions against kalmyks and other peoples were qualified as an act of genocide. Artilce 4 of this law provided that any propaganda impeding rehabilitation of peoples is prohibited, and persons responsilbe for such propaganda are subject to prosecution.