I am on record in many posts as saying that pacifism is not the same as cowardice, and have given examples.

Pacifism and non-violent resistance works if the oppressing society is mostly civilized. Civil rights in America worked because most Americans agreed with the principle.

Ghandi succeeded because Britain was civilized. A "Ghandi" in Nazi Germany during the height of its power would have been killed in obscurity.

There are many examples of amazing courage in the Nazi death camps. None of it would have changed anything. War did.

There is no "one size fits all" solution. It's obvious that someone like Lech Walesa, or Aleksandr Solzhenitsyn, or many others you could name, can make a big difference without war or violence. In other cases, only violence will do the job. Nobody was going to reform Nazi Germany, Pol Pot's Cambodia, Taliban Afghanistan, or Saddam's Iraq, peacefully from within.

Trying to tell one situation from the other is where leaders get gray hair. This is where we are now with Iran, and given what we know so far about that country, frankly I don't have the answers either.