a "heroic Ukrainian resistance against the Nazis and the Communists". After World War II, the UPA fought against Soviet and Polish government forces. During Operation Vistula in 1947, the Polish government deported 140,000 Ukrainian civilians in Poland to remove the support base for the UPA. In the struggle, Soviet forces killed 153,000, arrested 134,000, and deported 203,000 UPA members, their families, and their supporters. During and after the Cold War, Western intelligence agencies, including the CIA, covertly supported the OUN. History Background and creation In 1919, with the end of the Polish–Ukrainian War, the Second Polish Republic took over most of the territory claimed by the West Ukrainian People's Republic and the rest was absorbed by the Soviet Union. One year later, exiled Ukrainian officers, mostly former Sich Riflemen, founded the Ukrainian Military Organization (Ukrainian – Українська Військова Організація: Ukrayins'ka Viys'kova Orhanizatsiya, the UVO), an underground military organization with the goals of continuing the armed struggle for independent Ukraine. The UVO was strictly a military organization with a military command structure. Originally the UVO operated under the authority of the exiled government of the Western Ukrainian People's Republic, but in 1925 following a power struggle all the supporters of the exiled president Yevhen Petrushevych were expelled from the organisation. The leader of the UVO was Yevhen Konovalets, the former commander of the elite Sich Riflemen. West Ukrainian political parties secretly funded the organization. The UVO organized a wave of sabotage actions in the second half of 1922, when Polish settlers were attacked, police stations, railroad stations, telegraph poles and railroad tracks were destroyed. Attempted to assassinate the Poland's Chief of State Józef Piłsudski in 1921. In 1922, they organized 17 attacks on Polish officials, 5 of whom were killed, and 15 attacks on Ukrainians, whom they considered traitors, 9 of whom died, among them Sydir Tverdokhlib. UVO continued this type of activity, on a smaller scale later as well. When the League of Nations recognized Polish rule over western Ukraine in 1923, many members left the UVO. The Ukrainian legal parties turned against the UVO's militant actions, preferring to work within the Polish political system. As a result, the UVO turned to Germany and Lithuania for political and financial support. It established contact with militant anti-Polish student organizations, such as the Group of Ukrainian National Youth, the League of Ukrainian Nationalists, and the Union of Ukrainian Nationalist Youth. After preliminary