The Repatriation of Cossacks after the Second World War (see terminology) refers to the forced repatriation to the USSR of the Cossacks and ethnic Russians and Ukrainians who were allies of Nazi Germany during the Second World War.The repatriations were agreed to in the Yalta Conference; Stalin claimed the repatriated people were Soviet citizens as of 1939, although many of them had left Russia before or soon after the end of the Russian Civil War, or had been born abroad.