Defenders of FDR, who always had a soft spot for Stalin - "I like old Joe" - and defenders of Churchill, who understood completely what a barbarian Stalin was, claim that there was nothing the West could do. And besides, by consigning millions of East Europeans to slavery for generations we received in return a promise from Stalin to help defeat Japan in the pacific - eventually. Of course, Hiroshima made that chit worthless.
For example, Arthur Schlesinger Jr., the revered liberal historian who has always considered it part of his job description to carry more water than Gunga Din for Democratic presidents, responded to Bush's speech with the usual haughty incredulity. "The American president is under the delusion that tougher diplomacy might have preserved the freedom of small East European nations. He forgets the presence of the Red Army. No conceivable diplomacy could have saved Eastern Europe from Soviet occupation."
Jacob Heilbrunn was more splenetic in the Los Angeles Times, caterwauling about Bush's peddling of "right-wing mythology" and the "Ann Coulter school of history."
The history is debatable. Schlesinger's emphasis on the word "diplomacy" is revealing. He writes, "It was the deployment of armies, not negotiating concessions, that caused the division of Europe." But the concessions at Yalta were possible because America chose to let Stalin occupy Eastern Europe. If, for example, General Patton had had his way, much of the occupation wouldn't have been a fait accompli. Schlesinger & Co. argue that Yalta was a concession to the necessities of reality. I wonder if FDR's defenders think tougher diplomacy is similarly pointless regarding, say, the Israeli occupation of the West Bank? Israel has it now, so that should settle the issue.
It's ironic: Liberals celebrated Bill Clinton's numerous apologies for America's Realpolitik "mistakes" during the Cold War as a sign of great statesmanship. But when an apology reflects poorly on the mistake that basically launched the Cold War, they bang their spoons on their highchairs about any attempt to tarnish FDR's godhood.
This raises the larger moral point. After a war to end one evil empire, we signed a piece of paper accepting the expansion of another evil empire. And it happened at Yalta.