Hitler had an economic strategy, not a military strategy.
It appears to me that Hitler was a WWI soldier who was repeating WWI. The theory was that WWI had been lost by the “knife in the back” – the collapse of civilian support --, so Hitler’s strategy was to not expose German civilians to the economic effect of war. The German economy was not changed to a “war economy”, rather, the war was funded by debt and conquest, and the strategic plan was to feed Germany simply by starving the rest of Europe. France would take a long time to conquer, but Russia would not, because France had taken a long time to conquer, and Russia had collapsed and withdrawn from WWI.
So, what went wrong? The success of his early invasions, plus the drug habit, lead to a misplaced sense of invincibility, feeding the belief that no military strategy was required.
And the simplistic analysis of WWI. He thought that the only reason Germany was beaten was because of civilian collapse, and that he had a solution to that problem. He thought that the only reason Germany was beaten was because of civilian collapse, and that Britain and Russia and the USA could be pushed into the same failure.