Winston Churchill had said he would "sup with the devil" if it would help bring about victory [in WW2]. So he—and Franklin Roosevelt—did. They allied themselves with Stalin, even pretended, at least publicly, that he was a fine man and the Soviet Union an even finer place. Now, with the release of numerous documents from the National Archives about Stalin's murder of over twenty thousand Polish officers and intellectuals in the Katyn forest in 1940, we know in even more detail just how far they were prepared to go to extol and defend the Soviet Union.Heilbrunn goes on to observe that the newly released documents indicate that Churchill and FDR pretty much knew the Soviets were responsible for the massacre and worked to ensure that an investigation, which the Polish government-in-exile in London called for, would not occur. FDR and Churchill engaged in "a brutal act of realpolitik," Heilbrunn writes, adding that this shows they had given up on Poland's freedom before Yalta.
I agree with Heilbrunn's characterization of FDR's and Churchill's actions, but the puzzling thing about Heilbrunn's post is that he criticizes FDR and Churchill while also seeming to recognize that their alternatives were very limited: "they had a weak hand to play," he notes. In the spring of 1943, Heilbrunn observes, the Nazis discovered the Katyn massacre and, blaming the Soviets for it, hoped to use it to create a rift between Stalin on on hand and Roosevelt and Churchill on the other. "But Roosevelt and Churchill were having none of it," he writes.
Of course Roosevelt and Churchill were having none of it. In the spring of '43 Hitler's armies were still in the USSR. They were reeling from Stalingrad but not yet totally defeated. The battle of Kursk had not yet started. The overriding aim of Roosevelt and Churchill was to defeat Nazi Germany and there were few lengths to which they would not go in pursuit of that goal. They had to feel some considerable gratitude to the USSR (and, by extension, to Stalin) for repulsing Hitler's invasion at enormous human cost.
You really don't have to know much about World War II to know that, while it was being fought, ideals took a back seat to the perceived requirements of victory in the policy decisions of the main leaders, at least of the Allies. Churchill and FDR allied themselves with a murderous dictator and helped to cover up the Katyn massacre and no doubt would have covered up other crimes of Stalin that came to their attention in the course of the war (perhaps in fact they did). Churchill said that if Hitler invaded Hell, he (Churchill) would make a favorable remark about the Devil in the House of Commons. He was serious. In 1943 victory was still not certain and it is a bit bizarre to think that FDR and Churchill would have created a breach with Stalin over anything. Should they have done so? Not even Heilbrunn says that directly.
There were many individual acts of heroism and idealism on the battlefields (construing that word broadly) of World War II. But in the councils where policy was made and memorandums of state were written, I think it's probably safe to say that World War II was almost entirely 'brutal realpolitik'. It was, if anyone, Hitler who was the least guided by realpolitik, as he insisted on spending bureaucratic and financial and manpower resources on the machinery of the Holocaust long after it became clear that all of Germany's resources should have been going directly into its military effort if the Third Reich were going to have a chance of survival. It was Hitler who put his ideological aims above the dictates of military necessity. FDR and Churchill issued high-minded declarations like the Atlantic Charter, but basically they were focused on one thing: prosecuting the war to a successful conclusion. All other considerations got pushed aside. They were facing what they saw, with some considerable justification, as 'a supreme emergency', in Churchill's phrase, and they were going to do what they thought they had to do.
P.s. Stalin of course did a great deal of ideologically motivated killing too, but more before and after the war than during it (the Katyn massacre notwithstanding).