The Ukrainian Insurgent Army (, abbreviated UPA) was a Ukrainian nationalist paramilitary and later partisan formation founded by the Organization of Ukrainian Nationalists on October 14, 1942. During World War II, it was engaged in guerrilla warfare against the Soviet Union, the Polish Underground State, Communist Poland, and Nazi Germany. The insurgent army arose out of separate militant formations of the Organization of Ukrainian Nationalists—Bandera faction (the OUN-B), other militant national-patriotic formations, some former defectors of the Ukrainian Auxiliary Police, mobilization of local populations and others. The political leadership of the army belonged to the OUN-B. It was a perpetrator of the ethnic cleansing of Poles in Volhynia and Eastern Galicia, murdering tens of thousands of Poles and Jews, mostly women and children. Its official date of creation is 14 October 1942, the day of the Intercession of the Theotokos feast. From December 1941 to July 1943, the Ukrainian People's Revolutionary Army shared the same name (Ukrainian Insurgent Army, or UPA). Violence was accepted by OUN as a political tool against both foreign and domestic enemies of their cause, which would be achieved by a national revolution led by a dictatorship that would drive out occupying powers and set up a government representing all regions and social groups. The organization began as a resistance group and developed into a guerrilla army. In 1943, the UPA was controlled by the OUN(B) and included people of various political and ideological convictions. Furthermore, it needed the support of the broad masses against both the Germans and the Soviets. Much of its nationalist ideology, including the concept of dictatorship, did not appeal to former Soviet citizens who had experienced Stalinist dictatorship. Because of this opposition, at its Third Extraordinary Grand Assembly on 21–25 August 1943, the OUN(B) condemned "internationalist and fascist national-socialist programs and political concepts" as well as "Russian-Bolshevik communism", and proposed a "system of free peoples and independent states [as] the single best solution to the problem of world order." The new social program did not differ essentially from earlier ones but now emphasized a wide range of social services, worker participation in management, a mixed economy, choice of profession and workplace, and free trade unions. The OUN(B) affirmed that it was fighting for freedom of the press, speech, and thought. During its existence, the Ukrainian Insurgent Army fought against the Poles and the Soviets as their primary opponents. From February 1943,