What I mean by this is that when looking at the liberation of Europe, it seems that Poland played a fairly large role in helping the liberation by sending troops to the Western front and they were also present on the Eastern front. Furthermore there was a government in exile in London yet at the end of the war Poland lost territory to the USSR and was forced to become a USSR satellite state and adopt communism.
Did the Polish government expect to be "handed over" to the USSR or did they feel betrayed that they got the short end of the stick or am I just completely wrong on this subject?
I can offer some insight on this. To begin, I'll need to explain a little bit about the "Tehran Conference' of 1943. Essentially, the Tehran Conference was a meeting between Churchill, Stalin, and Roosevelt in the USSR's Iranian embassy. In this conference, they discussed strategy for the war. This included the redrawing of borders in some nations, particularly Poland. Stalin had some particularly... Soviet-centric ideas for eastern Europe. To put it in layman's terms, the West really needed Soviet aid to win the war. Due to their desperation, Winston Churchill and Theodore Roosevelt made significant concessions to Stalin. Such concessions included the support of the Yugoslav military, a Soviet-backed communist army, in their fight versus the Axis. This also included the West basically allowing Soviet Russia free reign over eastern Europe. To explain more specifically, Stalin pushed for the redrawing of Poland's eastern borders to the Curzon Line, named after the British secretary who drew it in 1920. This essentially allowed the USSR to annex much of modern-day Lithuania, Belarus, and the Ukraine. (It should be noted that the USSR also promised Lithuania the return of the Vilnius region following their co-operation with Soviet occupation during the war, which was of course untrue.)
In order to compensate the Polish government for the Communist annexation of their eastern regions, the Allied leaders agreed to allow Poland to annex German territory, as seen of the map. (The yellow regions were annexed from Germany.) These ideas were later ratified at the Potsdam agreement of 1945.
During Stalin's Great Purge, many Polish communists were killed. It wasn't until WWII that another Polish Communist movement was created, this time much more loyal to the USSR. There's a great article written by Michael Kaufman here that is a fantastic read about Poland's acceptance of communism. It essentially explains that in the deeply religious Poland, communism was not an established political ideology like it was in other eastern European nations, like Lithuania or Czechoslovakia. After WWII, Moscow-backed communists declared a provisional government in Poland. Understandably, there was much resistance, as like you said in this post, many Poles felt they were being betrayed by their liberators, and there was significant resistance in Poland until the fall of communism in 1989.
Sources:
U.S. Department of State. "The Tehran Conference, 1943 - 1937–1945". Milestones - Office of the Historian.
Simon Berthon, Joanna Potts (2007). Warlords: An Extraordinary Re-Creation of World War II. Da Capo Press. p. 285.
PolishGreatness.com - Image source
Overy, Richard (1996). Why the Allies Won. New York: W.W. Norton & Company. pp. 245–246.
Office of the Historian (2016). "The Tehran Conference, 1943". Milestones 1937–1945. U.S. Department of State.
Kaufman, Michael T. "40 Years of Communism in Poland: Stalin's House on a Soft Foundation." The New York Times. The New York Times, 17 Aug. 1989. Web. 30 Apr. 2017.
If you have any further inquiries I can try to expand some more.
