All kinds of movements can have terrorists. Some are successful. Some aren't. It's one of those things in life where for the most part a successful movement can retroactively be seen as good. That is, if they fail they are typically forever terrorists. And that's necessarily so. So yes had the American revolutionary or French revolutionaries failed they would have been terrorists. No question really. Sometimes things require a revolution to resolve deep societal issues that affect a good majority... Sometimes a few people want a revolution (using terroristic tactics) where most people don't agree with that. This is why two sets of people can see a given act as acceptable and not --and would invert their opinion if done back to them.