The fate of Poland was very important to both the United States and the Soviet Union, though the Soviet Union managed to maintain control of Poland. The war against the Nazis had left Stalin's army quite weak, and he was aware of Western hostility against his regime. Stalin desired a buffer state between the Soviet Union and the West. Stalin even envisioned this as early as 1939, when the Soviet Union invaded eastern Poland at the same time the Nazis invaded the western side. Stalin ordered many captured Polish officers killed in the Katyn Forest, as these people would form the leadership of any new Polish state. Stalin did not back the Polish government in exile in London, but rather a puppet state which he appointed after the Red army "liberated" the country. Stalin's desire for a weak Poland may have also stemmed from a small war fought between Poland the newly formed Soviet Union from 1919–1921.

Roosevelt, while enjoying the support during the war of a very vocal Polish lobby, delayed any action on the future of Poland. At Yalta, Roosevelt acknowledged the Soviet Union occupied Eastern Europe, but he hoped that the end of the war would bring free elections to the region. Roosevelt wanted the Soviets to help in a potential fight against Japan, which is why he did not antagonize Stalin. Roosevelt's plan was to negotiate with Stalin personally after the war, but the president died before war's end. Some Americans viewed the occupation of Poland as a sign of Stalin's aggression. When the Soviet Union began to clamp down on religious freedom and freedom of expression, more people started to speak out against Stalin's regime. Poland became one of the early contentious areas in what would be called the Cold War.

Poland was an important buffer zone between Germany and the USSR at the end of World War II. When the Allied leaders met in Yalta in 1945, President Roosevelt was very ill and would die soon thereafter, so he was not in the best state to negotiate. Stalin, on the other hand, was ascendant, as the Soviet army by this time was meeting little resistance from what was left of the German army in the east and was advancing rapidly towards Berlin. The Allied forces coming from the west were more bogged down and moving more slowly.

Although Stalin had the upper hand at that moment and although his country had by far sustained the worst losses in the war to that point, the United States nevertheless argued with him over the western border of Poland. Stalin wanted even more of Germany absorbed into Poland than the US could stomach. The Soviets, as it was, were able to incorporate a good chunk of east Germany into Poland, simply ejecting Germans and forcing them to move west. The Germans displaced were unhappy but accepted this, knowing that when the German army was invading the Soviet Union in 1941 it simply murdered most non-combatants in its path.

The USSR wanted as weak a Germany as possible, which meant keeping it small,and as big a buffer as possible between itself and Germany, understandable goals given Germany's savage surprise attack on it a few years earlier. The United States, however, wanted to keep the Russians contained and did not want communism spreading into Western Europe. A smaller, weaker Poland was in western European and American interests.

The fate of Poland was important to the US and the USSR because of the looming Cold War.

By the end of WWII, it was clear that relations between the US and the Soviets would not be very friendly.  Because of this, Poland became an important issue.  The Soviets wanted to control Poland for at least two reasons.  Partly, they wanted to spread communism.  In addition, they wanted a buffer between them and the West to help protect them from invasion.

The US, by contrast, was suspicious of the Soviet Union.  It felt that Poland should be democratic.  It wanted this partly because it wanted to prevent the Soviets from getting too much power.  It also felt that Poland had been abused by the major powers before WWII and it wanted to treat Poland more fairly.