21st April, 1920 - Ukraine fights for its independence
In exchange for the acceptance of a national border on the Zbrucz river, Polish Chief of State and First Marshal Józef Piłsudski promised the Ukrainian People's Republic military help in the Kiev Offensive against the Red Army. The Ukrainians gained more much needed help in the unlikely shape of a people's army led by their very own White Military Leader, a so-called "knight in rusty armour", Archduke Wilhelm von Hapsburg.
The odds were long because Kievan Rus was the origin of the Russian Civilization, and so the Ukrainians desperately needed to establish their hard-fought independence in this contested territory long before the Soviet State could win (let alone fully recover from) the bloody Russian Civil War. However this simple fact was not fully accepted by the All-Ukrainian Governing Council known as the Central Rada. They conspicuously failed to properly organize the three hundred thousand men that had spontaneously organized themselves into all-Ukrainian unit under the command of General Pavlo Skoropadsky.
When Skoropadsky failed to overthrow the Rada, he turned in desperation to the Colonel of the Ukrainian Sich Riflemen, Archduke Wilhelm von Hapsburg. Despite the ruthlessly expedient logic of "the enemy of my enemy is my friend" he was after all an aristocratic throwback to the pre-Great War Royal Houses of Central Europe that had brutally suppressed Slav nationalism for centuries. Yet against the odds, together with their Polish allies, they launched an unlikely bid to save Independent Ukraine from Russian chauvinism in its latest guise, Communism. In achieving this goal, they changed the future of Europe by establishing a cordon sanitaire between the totalitarian rogue states of Nazi Germany and Soviet Russia.
Addendum by Jeff Provine:
Hapsburg had initially determined the Polish treaty to be a betrayal by Western Ukraine, the revolution ousting the Rada proved to quell his feelings. The treaty stood with the new government, and Hapsburg climbed the military ladder by leading multinational forces to eventually drive out Russian threats. Many called for Wilhelm to become king, but "Vasyl Vyshyvani" as he dubbed himself refused out of his respect for commoners, although his overwhelming popularity gave him king-like powers in politics in the east.
In 1938, another European leader, Adolf Hitler, approached Ukraine about breaking off its treaty with Poland and retaking territory lost in the 1920 agreement. The Ukrainians came into agreement, but only on the condition of a new alliance that forced Germany into an anti-Soviet stance. Poland fell, bringing Western Europe to war with Germany at an inopportune time as alliances demanded German forces aid Finland in its own war with the Soviets alongside Ukrainian troops.