I think Germany thought they could convince the west to join them to defeat Russia.
Negative. Hitler straight up expected the Soviet Union to be a pushover.
Between 1914 and 1917, the German Heer defeated the Russian Empire so soundly that it's entire military and economy collapsed, resulting in a civil war that unseated the Tsar and resulted in the formation of an entirely new state.
Hitler also considered the Slavic people to be "Asiatic", and therefore "inferior, naive, eager to be subservient, and less intelligent" (quotes added to make it clear this is according to Nazi racial ideology and I'm not claiming to believe such nonsense myself). The evidence of this, in their mind, was how naive Stalin was to make multiple agreements with them even after they had formed an alliance specifically to stand against him (if unfamiliar, see
Anti-Comintern Pact) and how he had "purged" all of his best leaders. It's also worth noting that what we know about the planned invasion includes absolute disdain for Soviet manufacturing capability, to the point it was never really considered.
France was seen as a far more powerful adversary in every way, and Germany had conquered it in 47 days. Hitler assumed the Soviet Union would fall as quickly or quicker, and he did have some generals of the German High Command agreeing with him. That's why they didn't have any winter equipment ready. It wasn't that they forgot Russian winters are cold, they literally thought Moscow would fall in a month or less, certainly no more than 2 or 3.
The plan was to defeat the Soviets in weeks and that would convince the British to surrender, effectively ending the war. Then starve the Russians to death and redistribute that land to the German people.
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