[hellbender]

Yes, physical stress (including poor diet) and poor environment seem to play a big role in typhus. That's why I find it hard to believe that typhus alone beat the French. Their campaign went downhill from the very beginning. Their supply lines were too long and subject to Russian guerilla attacks, and they couldn't live off the land due to the Russian scorched-earth policy. Also, as your quote shows, cold temperature favors the disease.

Napoleon's big successes were all in highly developed western Europe. He didn't do so well in guerilla wars in backward countries.

[SunkenCiv]

Napoleon peaked early in his career as supreme field commander. If he’d had more patience and aptitude for politicking, he’d have been better off, and so would have Europe. OTOH, we wouldn’t have “The 1812 Overture”, so...

[SunkenCiv]

Their supply lines were too long and subject to Russian guerilla attacks, and they couldn't live off the land due to the Russian scorched-earth policy.

/bingo