This is a tough question. Sometimes when you overthrow someone who's causing much damage to a country's interests you end up helping some other creep get into power. This is something to think about long and hard before taking action.
Another problem is the idea of interfering in a country's affairs. This is something that should only be done in extreme situation. I'm not sure if America would have made the same choices if it new that Iraq doesn't have non conventional weapons.
In short I don't have a clear opinion on this one but i definitely think that it isn't something to run into.