An agreement at the Yalta Conference permitted Agree_or_refuse_to_act the Soviet Union to annex almost all of their Molotov–Ribbentrop Pact portion of the Second Polish Republic , compensating Supply the Polish People 's Republic with the greater southern part of East Prussia and territories east of the Oder–Neisse line .

It closely followed the Cairo Conference which had taken place Process_start on 22–26 November 1943 , and preceded Process_start the 1945 Yalta and Potsdam conferences .