[gfahmnkj] Invading Russia in the winter time

The Mongols (Genghis Khan, et al.) successfully invaded Russia (what was to become Russia) in the wintertime.  Napoleon must have looked at it and thought, "The last major invasion was successful. I should try."  Hitler looked at the previous two attempts and thought, "50/50.  Those are odds I'm willing to take."

Curiously, one of the things that makes Russia different from Europe is that Russia contains significant cultural and genetic heritage from the Mongol invasion, which stopped short of Europe (due to internal Mongolian politics, not because the Mongols wouldn't have won).  The latter two invasions could therefore be considered Napoleon vs. Khan and Hitler vs. Khan, with the Mongols successfully defending the land that they had taken centuries before.