"Although the [UNR] was unable to contribute real strength to the Polish offensive, it could offer a certain camouflage for the naked aggression involved. Warsaw had no difficulty in convincing the powerless Petliura to sign a treaty of alliance. In it he abandoned his claim of all territories [...] demanded by Pilsudski. In exchange the Poles recognized the sovereignty of the UNR on all territories which it claimed, including those within the Polish frontiers of 1772 – in other words, much of the area Poland demanded from Soviet Russia. Petlura also pledged not to conclude any international agreements against Poland and guaranteed full cultural rights to the Polish residents in Ukraine. Supplementary military and economic agreements subbordinate the Ukrainian army and economy to the control of Warsaw." Richard K Debo, Survival and Consolidation: The Foreign Policy of Soviet Russia, 1918–1921, pp. 210–211, McGill-Queen's Press, 1992, ISBN0-7735-0828-7.
Encyclopædia Britannica, Russo-Polish War in Encyclopædia Britannica [This war was a] military conflict between Soviet Russia and Poland, which sought to seize Ukraine […]Although there had been hostilities between the two countries during 1919, the conflict began when the Polish head of state Józef Pilsudski formed an alliance with the Ukrainian nationalist leader Symon Petlura (April 21, 1920) and their combined forces began to overrun Ukraine, occupying Kiev on May 7.
