@fresco,
You misspelled caviar.
It's a bit much to suggest that Stalin's attitude was cavalier. It was calculating and self-serving. As far as Poland is concerned, he likely thought to erect a buffer between himself and Germany, and of course his attitude was "Poland be damned." He was rather inept, though, and the initial success of the German invasion a little more than a year and half later is evidence of his lack of military acumen. Unlike Hitler, however, Stalin could and did learn, and was eventually able to deal with the near disaster of the German invasion. In large measure, that was because of the fecklessness of Japan as an "ally" of Germany. In 1941, Japan was soundly defeated by a large Soviet army near the border with Mongolia. Japan completed a neutrality agreement with the Soviet Union. When it became clear that Japan would honor the agreement, and was irrevocably committed to its southeast Asia adventure, Stalin was able to transfer more than 100,000 troops to the European Soviet Union, which stopped the Germans at the gates of Leningrad and Moscow. The number of naïve fools in power in that war is incredible. The Japanese were said to have been surprised when the Soviet Union declared war on them in 1945. Manchuria was invaded by Soviet troops (a token force--nothing more was needed at that stage) one hour after the declaration of war.
That there was a cynical
realpolitik operating in Moscow, as in Berlin and London, at that time should surprise no one. Churchill was the biggest, loudest-mouthed anti-Bolshevik in England in the 1920s and -30s. However, by the time he took office in 1940, he'd have allied himself to Beelzebub in order to defeat Hitler. One could be forgiven for suggesting that that is exactly what he did.
I don't recall anyone suggesting that Stalin should be thanked. He obviously was not prepared for the invasion of nearly four million German and German-allied troops, and he obviously had not adequately prepared for the scale of the invasion, nor given thought to the possibility of invasion on so wide a front, from the Baltic to the Black Sea. I suspect, but can't say to a certainty, that he was surprised that Romania, Hungary and Italy contributed significant forces, along with token forces from Slovakia and Croatia.
In the event, Stalin did what he had to do, given that the Soviet Union had been invaded. The only nation which can be said to have acted "honorably" in the entire
hexenkessel of that war in the east is Finland. Finland allied itself to Germany and accepted aid from the Germans; but having recovered the land which the Soviets had taken from then in the Winter War, Finland was reluctant to become involved in major operations against the Soviet Union--once again,
realpolitik is a bitch. Churchill reacted with his usual bluster, and was in no position to do anything. Roosevelt was also in no position to do anything, and Finland publicly rejected his calls for the Finns to withdraw to their 1939 borders. However, a secret agreement was concluded between the Finns and the Americans, and Finland agreed to cease their operations against the Murmansk railroad. (Before England and the United States fiddled Iran, and set up a puppet government under a paper Shah, that was the only way to get supplies to the Soviet Union. The sacrifice of British and American merchant seamen on the "Murmansk Run" has become one of the legends of the war.)
The Finnish border was just 25 miles from Leningrad. Had Roosevelt and Finland not come to an understanding, it is difficult to see how Leningrad could have held out. Holding Leningrad was absolutely critical to defending the Soviet Union.
From the time of the Normandy invasion, and almost until American and Soviet troops met at the river Elbe, German troops outnumbered Allied troops in western Europe. It was not until March of 1945 that the American build-up had reached a point at which Allied troops in the west were no longer outnumbered. There were two reasons that it was possible for Eisenhower to take such a calculated risk. One was air supremacy--the German troops used to say if you see a white plane, it's the Tommies, if you see a black plane, it's the Amis (Americans), and if you don't see any planes at all, it's the Luftwaffe. The other reason was the millions of troops tied up in the Soviet Union.
In the end, the biggest friend of the western Allies in Europe was Hitler. His stupidity and pig-headed insistence on no retreat policies assured the eventual defeat of Germany. I don't see how it could have been done without the Red Army, but maybe one of you holier-than-thou geniuses could explain that.