and White (or Red) Russia. The UPR was not recognized by the Allies. The British and the French warned Poland that the treaty with the UPR amounted to irresponsible adventurism, because Poland lacked strong economic foundations, industry, or stable finances, and was not in a position to impose a new geostrategic situation in Europe. The UPR was supposed to subordinate its military and economy to Warsaw. Ukraine was going to join the Polish-led Intermarium federation of states in central and eastern Europe. Piłsudski wanted a Poland-allied Ukraine to be a buffer between Poland and Russia. Provisions in the treaty guaranteed the rights of the Polish and Ukrainian minorities within each state and obliged each side not to conclude international agreements against each other. Piłsudski also needed an alliance with a Ukrainian faction as cover for the action perceived abroad as military aggression. As the treaty legitimized Polish control over the territory that Ukrainians viewed as rightfully theirs, the alliance received a dire reception from many Ukrainian leaders, ranging from Mykhailo Hrushevsky, former chairman of the Central Council of Ukraine, to Yevhen Petrushevych, the leader of the West Ukrainian People's Republic who was forced into exile after the Polish–Ukrainian War. UPR Prime Minister Isaak Mazepa resigned his position in protest of the Warsaw agreements. While to many protesting WUPR activists Petliura was a traitor and renegade, the divided UPR circles quarreled about the merits of the Polish–Ukrainian alliance. Preparations Piłsudski resolved to realize his political objectives by way of military determinations. For political reasons, he chose to launch an attack on the southern, Ukrainian front, in the direction of Kiev. He had been assembling a large military force throughout the winter. He had become convinced that the Russian White movement and its forces, largely defeated by the Red Army, were no longer a security threat to Poland and that he could take on the remaining adversary, the Bolsheviks. The Red Army, which had been regrouping since 10 March, was not fully ready for combat. One important factor that limited the Soviet response to the Polish attack was the peasant Pitchfork uprising that took place in February–March and was taken very seriously by the Bolshevik leadership. It distracted the Soviet Commissar of War Leon Trotsky so much that he had temporarily left Ukraine and Belarus poorly defended. The Kiev Expedition, in which 65,000 Polish and 15,000 Ukrainian soldiers took part, commenced on