When the Yalta conference was held, the Soviets were in the Baltic States and Eastern Europe and the other allies were not. Yalta may have simply recognized reality: the British and Americans weren’t going to fight another war to drive the Soviets out. From Martin Sieff at strategic-culture.org:
Politically aware Americans, especially self-proclaimed “tough” neo-liberals and neo-conservatives have had a hate obsession with the Crimea for 73 years since proclaiming the myth of an “evil” sell-out of Eastern Europe that supposedly took place at the Yalta summit conference in February 1945 between Josef Stalin, Winston Churchill and a dying US President Franklin Roosevelt.
Instead, as is often the case in the age of George Orwell’s “big lie” in modern America and Britain, the opposite was the case. The Yalta conference was a triumph of realpolitik that kept the global peace between the superpowers almost three quarter s of a century so far.
It is, therefore enormously ironic that the peace of the world should now be threatened over US and UK outrage in particular over Russia asserting its legal and sovereign rights after a blatant breach of agreements and sovereignty by the Ukrainian vessels in Kerch Strait separating Crimea from mainland Russia.
The kneejerk US and UK reactions, based on mindlessly swallowing generations of dangerous mythmaking by both Republicans and Democrats in the United States and by the revered demigod Winston Churchill in Britain is that at Yalta Roosevelt cynically – and possibly in full senility – “sold out” all the countries of Eastern Europe to Stalin and thereby threatened the survival of the West.