The Ukrainian Insurgent Army was a Ukrainian nationalist partisan formation founded by the Organisation of Ukrainian Nationalists (OUN) on 14 October 1942. The UPA launched guerrilla warfare against Nazi Germany, the Soviet Union, and both the Polish Underground State and Polish Communists. The UPA carried out massacres of Poles in Volhynia and Eastern Galicia, which are recognized by Poland as a genocide. The goal of the OUN was to establish an independent Ukrainian state. This goal, according to the OUN founding declaration, "was to be achieved by a national revolution led by a dictatorship" that would drive out occupying powers and then establish a "government representing all regions and social groups"; OUN accepted violence as a political tool against enemies of their cause. In order to achieve this goal, a number of partisan units were formed, merged into a single structure in the form of the UPA, which was created on 14 October 1942. From February 1943, the organization fought against the Germans in Volhynia and Polesia.