An interesting scenario would have been if US was postponed for Japan and the land of the rising sun had decided to team up with Hitler in a pincher attack or a two front attack on Stalin:
nationalww2museum.org/war/articles/hitler-nazi-germany-pearl-harbor"The German defeat in front of the Soviet capital was the result of many factors, but above all of a serious German logistical overstretch, with replacements lagging behind losses, spare parts and fuel hard to come by, and reinforcements altogether absent. The drive on Moscow petered out in late October, with the arrival of the autumn rains, restarted briefly when the mud froze, then got stuck together with the hard freeze and snow of mid-November. The Soviets even liked to brag about two of their most stalwart and heroic commanders: General Mud and General Winter. By any reasonable standard, the time had come for the Wehrmacht to take stock, consolidate a good defensive position, and then use the new line as a jumping off point for an offensive in 1942.
But that did not happen-quite the opposite, in fact. The Germans kept pressing forward, suffering soaring casualties for decreased gain, and today we know one of the reasons why: Hitler and his staff kept driving the troops onward in order to impel the Japanese to enter the war.
The Führer knew the Japanese were considering a strike on the United States. Back in March, he had promised Japanese Foreign Minister Matsuoka Yosuke to support the Rising Sun in any war it launched on America. The Japanese, disappointingly, had refused to jump, deciding to spend the year in seemingly endless negotiations with Washington. They refused to jump in July, when the Wehrmacht was carving up the Red Army like a roast, and they were hardly going to do so if the Germans suddenly looked like losers in front of Moscow. Hitler desperately wanted Japan in the war. He was impressed with its military tradition, its never-say-die soldiers, and, of course, its big blue water navy, the wartime Reich's most serious strategic deficiency. A Japanese attack would keep the United States distracted and reduce the amount of American materiel flowing to the Allies: all good things for Berlin."
I dont know this seems kind of far streched to me. I always thought hitler was just cocky ad impatient and thats why he didnt dig in in late 41. It is possible though that he knew pearl harbour will happen way ahead of when it did? and he was trying to change their minds to attack the soviet union instead? maybe if hitler managed to take it right before winter truly hit and he had to dig his troops in late 41 japan would have done it?
