Jane Caplan describes the Nazi police state.
Jane Caplan, Nazi Germany: A Very Short Introduction (New York: Oxford University Press, 2019), 51-52
Brute force saturated and sustained the Nazi political system. Neither Hitler’s dictatorship nor his most radical policies would have been possible without one of the most fateful shifts in the distribution of power after 1933. This was the takeover of the German police and security forces by Heinrich Himmler and their alignment with the SS, through which the SS was transformed into the most powerful and dreaded organization in the ‘Third Reich’. This transformation represented virtually a second, creeping seizure of power. It foreshadowed a comprehensive system of terror that would not only anticipate and neutralize alleged threats to the body politic, but also justify the powerful security apparatus this demanded.