Question

What made Germany’s invasions of Europe difficult to stop during World War II?

Answer 1

It is because of BLITZKRIEG.

Germany quickly overran much of Europe and was victorious for more than two years by relying on a new military tactic called the "Blitzkrieg" (lightning war). Blitzkrieg tactics required the concentration of offensive weapons (such as tanks, planes, and artillery) along a narrow front.

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