Can anyone recommend a book or study explaining why people don't stand up to dictatorships?

An example would be why more individuals did not necessarily simply stand up and say "no" to the Soviet take over of many eastern bloc countries (although, eventually they did, such as the Prague Spring and Velvet Revolution). I am looking for an empirical ysis, not necessarily something philosophical (like Machiavelli). Some do stand up, but the question is, why do they not always do so en me? Thanks! PS: If you are part of the international community, or were, please feel free to chime in with your thoughts (no judgment!).