You're confusing WWII germany and post WWII germany. Stasi was the ministry for homeland security of East-Germany in the post-WWII era untill the fall of the wall (1950- 1989). It has nothing to do with the Nazis (1930ish to 1945) The Stasi was a way to take hold of the country and get it stable again after the nazi regime fell. Though they did that by turning _EAST_ (not west) germany into a police state.