Political map of Europe & the Mediterranean 19 April 1946 (The Iron Curtain Descends): By the time the Allies (Allies of World War II) met at Potsdam (Potsdam Conference) in September 1945, it was clear that Stalin (Josef Stalin) intended to retain tight control over the eastern European countries (Eastern Bloc) Soviet armies had occupied during the War (World War II). Western distrust grew with Soviet insistence on pushing Poland westward into lands containing millions of Germans (Oder-Neisse Line) not to mention increasing communist activity (Communist) in Iran (Iran Crisis of 1946), Greece (Greek Civil War) and on the Italo-Yugoslav border (Free State of Trieste).