Hitler renounced the Polish-German Pact of Non-aggression. German policy changed drastically after Hitler annexed Sudetenland. In October 1938, German Foreign Minister Ribbentrop proposed the option of renewing the Pact in exchange for allowing the Free City of Danzig (Gdansk today) to be annexed by Germany, as well as permitting the construction of an extraterritorial motorway and railway through the Polish Corridor, with Germany accepting Poland's postwar borders. Poland refused. On September 1, 1939, Germany invaded Poland, starting World War Two.
Stanislaus Orlemanski, a Polish-American priest from Springfield, Massachusetts traveled to Moscow at the behest of Stalin himself. Marshal Stalin was looking for support among the Polish diaspora, (Polish people who have emigrated to nations across the world) and suggested that Orlemanski might be a good candidate for a cabinet post in a new post-war Polish government. Incidentally, Orlemanski was active in forming the Kosciusko League, which funneled money and weapons to the remnants of the Polish Army. Nevertheless, he accepted Stalin's invitation as an opportunity to encourage rapprochement between the Vatican and Moscow. The meeting with Stalin left Orlemanski feeling assured that Russia was committed to building a free, democratic self-governing Poland. Even US President Franklin Roosevelt got caught up in discussions of how the Soviet regime might embrace religion. Upon his return to Sprinfield, Orlemanski was relieved of his priestly duties, and permitted to return only on the promise of silence on the subject of his trip to Moscow. The American public at large considered this charade as merely a publicity stunt by Stalin. Orlemanski's naivety was reflected in these comments, “Stalin tried to use me and I tried to use him, for the good of my Church. He won and I lost.”
Operation Vistula began. For the next three months and with Soviet approval and aid, about 141,000 Ukrainians from Bieszczady and Low Beskids were forcibly resettled to former German territories (ceded to Poland at the Yalta Conference at the end of World War II). The Soviet objective was the removal of material support and assistance to the Ukrainian Insurgent Army. Operation Vistula brought an end to hostilities. On August 3, 1990, the Polish Senate adopted a resolution condemning the postwar Polish government's Operation Vistula. In response, the Ukrainian Parliament (Verkhovna Rada) adopted the statement of understanding of the Polish Senate resolution as a serious step towards the correction of the injustices towards the Ukrainians in Poland. In the same resolution the Rada condemned the criminal acts of the Stalinist regime towards the Polish people. In 2007, the President of the Ukraine, Viktor Yushchenko, and the President of Poland (the late Lech Kaczyński) condemned the Operation Vistula as a violation of human rights.