Remove Christianity and Civilization would soon disappear.

[The Valkyrie]

Here, let me fix that for you:
cultures and nations get wiped out by those possessing better technology and weapons than their own.

Germans had the best at the time and still lost..

They had an incompetent commander who ignored the advise of his generals, started a war on a second front while still fighting multiple enemies and against a much larger but equally fanatical enemy.

THat's called a recipe for disaster