It is assumed that the agreement on Outer Mongolia and the aforementioned port and railway railways will require the approval of Generalissimo Chiang Kai-shek. The President will take steps to obtain this agreement on the advice of Marshal Stalin. On August 23, 1939, just before the start of World War II (1939-45) in Europe, the enemies of Nazi Germany and the Soviet Union surprised the world by signing the German-Soviet non-aggression pact, in which the two countries agreed not to take military measures against each other to… On March 1, Roosevelt assured Congress: « I come from Crimea with the firm conviction that we have begun on the road to a world of peace. »  However, the Western powers soon realized that Stalin would not keep his promise of free elections for Poland. After receiving considerable criticism in London after Yalta of the atrocities committed by Soviet troops in Poland, Churchill wrote a desperate letter to Roosevelt in which he referred to the large-scale deportations and liquidations of opposition Poles by the Soviets.  On March 11, Roosevelt replied to Churchill and wrote, « I am sure we must stand firm on a correct interpretation of Crimea`s decision. They rightly believe that neither the government nor the people of this country will support participation in fraud or mere deception by the Lublin government, and the solution must be as we imagined it in Yalta.  In the spring of 1945, Churchill had ordered an emergency military intervention plan (war against the Soviet Union) to reach a « square agreement for Poland » (Operation Unthinkable), which led to a May 22 report that reported unfavourable success rates.  The report`s arguments included geostrategic issues (possible Soviet-Japanese alliance that led to the transfer of Japanese troops from the mainland to the native islands, threat to Iran and Iraq) and uncertainty about land battles in Europe.  In return, Stalin promised that three months after the defeat of Germany, the Soviet Union would enter the Pacific War.
Later, in Potsdam, Stalin promised President Truman to respect the national unity of Korea, which would be partially occupied by Soviet troops. The initiative to convene a second « Big Three » conference came from Roosevelt, who had hoped for a meeting before the US presidential elections in November 1944, but later pushed for a meeting in early 1945 at a neutral location in the Mediterranean. Malta, Cyprus and Athens have been proposed. Stalin, who insisted that his doctors oppose long journeys, rejected these options.  Instead, he suggested meeting instead in the Black Sea city of Yalta in Crimea. Fear of Stalin`s plane also contributed to this decision.  Yet Stalin formally referred to Roosevelt as the « host » of the conference; All plenary sessions should take place in the American accommodation of the Livadia Palace, and Roosevelt, without exception, sits in the center of the group photos (all taken by Roosevelt`s official photographer). Churchill defended his action in Yalta in a three-day parliamentary debate that began on 27 February and ended with a vote of confidence. During the debate, many MPs criticized Churchill and expressed deep reservations about Yalta and his support for Poland, 25 of whom drafted an amendment to protest the agreement.  The Soviets also wanted the surrender of Karafuto and the Kuril Islands, which were taken over from Russia by Japan during the Russo-Japanese War (1905), which was also agreed.