Steve wrote:Prior to Yalta the British Foreign Minister and the US Secretary of State met on Malta. Both ministers expressed disapproval of the territorial demands made by the provisional Polish government in Pravda. A US Memorandum stated that “We should resist vigorously efforts to extend the Polish frontier to the Oder Line or to the Oder – Neisse Line”. The Western Allies envisioned a settlement that gave Poland East Prussia except for the Konigsberg area, Danzig, German Upper Silesia and the eastern tip of Pomerania.
At Yalta Stalin and Molotov proposed a border running along the Oder and Western Neisse plus Stettin on the west bank of the Oder. Churchill protested against this. Later Roosevelt suggested that the Polish frontier be pushed up to the Oder but not to the Western Neisse. Churchill conceded “the lands desired by Poland to the east of the Oder”.
Roosevelt seemingly made this concession in the hope that Stalin would reciprocate by allowing free elections and a democratic Poland. On his return to America he said “The limits of the Western border will be permanently fixed in the final peace conference”.
Churchill said in parliament after he returned: - “In the North she will certainly receive, in the place of a precarious corridor, the great city of Danzig, the greater part of East Prussia West and South of Konigsberg, and a long, wide sea front on the Baltic. In the West she will receive the important industrial province of Upper Silesia and, in addition, such territories to the east of the Oder as may be decided at the peace settlement to detach from Germany after the views of a broadly based Polish Government have been ascertained”.
At Potsdam Churchill was totally opposed to the Oder – Western Neisse border. When he departed because of UK elections the Americans made a deal. In return for certain concessions by Stalin they would accept the Soviet position on the border. At the end of the conference it was agreed that the final delimitation of the border should await the peace settlement.
From “Nemesis At Potsdam” by Alfred M.de Zayas and “The Eagle Unbowed” by Halik Kochanski.
The Poles were lucky Churchill was not deciding where the border would run.
Britain and the US were NOT in a position to opose or not oppose anything: Stalin ruled in this region and Stalin would decide about the borders.That the Polish border,that Poland would go to the west was a logical consequence of the German defeat,which was caused by the German decision to start the war : vae victis .