Why did the Yalta conference significant concessions were made to the Soviet Union because?

The Yalta Conference, held in February 1945, was significant for the concessions made to the Soviet Union primarily due to the Allies' desire to secure Soviet participation in the fight against Japan and to ensure a cooperative post-war order. Leaders Franklin D. Roosevelt, Winston Churchill, and Joseph Stalin sought to maintain unity among the Allies, which led to compromises on issues such as the division of Eastern Europe and the establishment of Soviet influence in the region. These concessions were also seen as a way to stabilize Europe after the war, albeit at the cost of facilitating the onset of the Cold War tensions.