The Americans suspected Stalin of having invented the bombing as an excuse to send Roosevelt to the Soviet embassy. Mike Reilly, the head of Roosevelt`s secret service, advised him to go to the Soviet or British embassy for his safety. One of the underlying factors that influenced their decision was the distance Churchill and Stalin had to travel to meet at the U.S. Embassy. Harriman reminded the president that Americans would be held accountable if Stalin or Churchill were assassinated while traveling roosevelt throughout the city.  Previously, Molotov had agreed to hold all meetings at the U.S. Embassy, as the trip was difficult for Roosevelt. The moment Molotov announced an attack later that night aroused suspicions that his motives were to keep Stalin safe in the guarded walls of the Soviet embassy.  Harriman questioned the existence of an attack, but asked the president to relocate to avoid the perception of putting Churchill and Stalin in danger. Roosevelt did not believe there was a credible death threat, but agreed to do so so that he would be closer to Stalin and Churchill.  Life in the Soviet embassy also allowed Roosevelt to gain more direct access to Stalin and establish his trust.
Stalin liked having Roosevelt at the embassy because he eliminated the need to travel outside the compound and made it easier for him to spy on Roosevelt. The Soviet embassy was guarded by thousands of secret policemen and was next to the British Embassy, which allowed the Big Three to meet safely.  Churchill proposed to Stalin a move to western Poland, which Stalin accepted, which gave the Poles the German country westward and abandoned the marshes to the east, while offering the Soviet Union a territorial buffer against invasion. Churchill`s plan provided for a border along the Oder and Eastern Neisse, which Churchill said provided Poland with fair compensation for the eastern border regions.  As the war ended in Europe, Roosevelt knew that the United States was still facing a long-term struggle against Japan during the Pacific War and wanted to confirm Soviet support to limit the duration and sacrifices in that conflict. In Yalta, Stalin agreed that Soviet troops would join the Allies in the war against Japan within „two or three months“ after Germany`s surrender. The Tehran conference took place in November 1943. Tehran is in Iran today. At the time of the Tehran conference, the Second World War was still raging and the Allies` hopes of victory were slim. That is why most of the discussions at the Tehran conference focused on how to win World War II.
We talked about what would happen after the war with Europe, but it was mainly about Germany. The agreement in principle, i.e. no formal agreement, was that only unconditional surrender would be accepted by the Allies. There was also the idea that German should be left as a weak nation after the war and that the lands that had conquered it during the expansion of Germany should be returned to the countries that had lost it. By March 1945, it had become clear that Stalin had no intention of keeping his promises regarding political freedom in Poland.