What happened when Hitler tried to invade the Soviet Union? Why was this so difficult?

On June 22, 1941, Adolf Hitler launched his armies eastward in a massive invasion of the Soviet Union: three great army groups with over three million German soldiers, 150 divisions, and three thousand tanks smashed across the frontier into Soviet territory.

c. wright mills's sociological imagination suggest investigating to explain this increase?

states grant a variety of local governments power to meet residents’ needs (source: apex learning). hope this !