 The Ukrainian Insurgent Army ("UPA"), a Ukrainian nationalist force and the military arm of the Organization of Ukrainian Nationalists ("OUN"), which some historians consider fascist, decided in 1943—while fighting the Germans, Soviets and Poles, who they saw as occupiers of the future ethnically-pure Ukrainian state—to direct most of its attacks against Poles and Jews.One of UPA's leaders, Stepan Bandera, and his followers, concluded that the war would end in the exhaustion of both Germany and the Soviet Union, leaving only the Poles – who laid claim to East Galicia (viewed by the Ukrainians as Western Ukraine, and by the Poles as Eastern Poland)—as a significant force, and therefore had to be weakened before Poland rose again.Poland's plans to restore its prewar borders were opposed by the Ukrainians, and some Ukrainian groups' collaboration with Nazi Germany had discredited their partisans as potential Polish allies.