The USSR was supplied by the West to keep them in the war; they did much of the fighting but for Americans the price (beyond all the food and arms sent) was fighting Japan with no help from the USSR. The Soviets could concentrate on the Eastern Front because they observed a ceasefire with Imperial Japan until the last months of the war.
FWIW, “Soviets” is a more accurate term then “Russians” - especially by the end of the war, when so many “European” Soviets had been killed that they were using many Far Eastern minorities as troops.
In terms of Hitler being “insane”, I suspect his determination to fight until the death was influenced by Mussolini’s execution and the subsequent displaying of his body afterwards. Hitler had a bizarre notion that the Soviets were going to display him naked in a cage in Moscow after the war...
> In terms of Hitler being “insane”, I suspect his determination to fight until the death was influenced by Mussolini’s execution and the subsequent displaying of his body afterwards. <
As you probably know, the Allies guaranteed Hirohito’s personal safety. That was to sweeten the pot - to help induce the Japanese to surrender.
Suppose the Allies had done the same thing with Hitler, say after the Battle of the Bulge. Let him escape to Switzerland or Argentina. Stalin never would have gone for that. But it would make for an interesting historical novel.