Be reflective if you must be armed
On Tyranny, chapter 7
Police and military are often armed, and their power can be easily abused by secret police forces organized by authoritarian regimes to help do their dirty work. The Soviet NKVD and the German SS relied greatly on local police and military forces to carry out thousands of murders.
And so, armed police and military must be aware of the position they hold, and be on guard when asked to do irregular things. The fear of punishment or death when faced with such orders can be great, but standing out and refusing to conform prevents authoritarian forces from being able to do their worst.