In response to the February 1945 Yalta Conference directives , a Polish Provisional Government of National Unity was formed in June 1945 under Soviet auspices ; it was soon recognized by the United States and many other countries . The Soviet domination was apparent from the beginning , as prominent leaders of the Polish Underground State were brought to trial in Moscow ( the " Trial of the Sixteen " of June 1945 ) . In the immediate post-war years , the emerging communist rule was challenged by opposition groups , including militarily by the so-called " cursed soldiers " , of whom thousands perished in armed confrontations or were pursued by the Ministry of Public Security and executed . Such guerillas often pinned their hopes on expectations of an imminent outbreak of World War III and defeat of the Soviet Union . The Polish right-wing insurgency faded after the amnesty of February 1947
Yalta Conference
Yalta Conference
History of Poland