The best solution is for Iran and their insane leaders to be overthrown from within. Anything the rest of the world could do to speed up an internal revolution would be welcomed by all.
Perhaps. But we've given them 27 years to do so, and now Iran is about to get the bomb. It can't be allowed. This isn't an "Imperialist American" speaking, but a person who realizes crazy people running a country under the thrall of crazy Islam will use any weapons it can get it's cloven hooves on.
From what I've read on this situation, the internal resistance lacks organization, weapons, and communications capabilities. The rulers have a "fear" society in place where dissent is punished. There is not time to develop an internal revolution. This could be wrong, or disinformation, but that is what I have read.