Which action taken by both Hitler and Napoleon is considered by historians to be a strategic military error?

1 Answer
May 1, 2016

The invasion of Russia/Soviet Union.

Explanation:

Napoleon invaded in 1812, Hitler in 1941. Both invasions resulted in defeat and retreat due to, amongst other things, the sheer size of the country and the logistic problems this causes and the severe Russian winter which neither had prepared their armies for.