After WWII ended, journalist Milton Mayer investigated how Germany had become a totalitarian state. He wanted to know why, as Adolf Hitler’s Nationalist Socialist Party amassed power and drove country to war, Germans didn’t stand up for their rights. https://link.medium.com/PVTwx9SeJ9 

His study of these men, They Thought They Were Free, was released in 1955. As historian Richard J. Evans wrote in 2017, it “still stands as a timely reminder of how otherwise unremarkable and in many ways reasonable people can be seduced by demagogues and populists ......

...: and how they can go along with a regime that commits more and more criminal acts until it plunges itself into war and genocide.”