Look back at Hitler and his rise to power and all of the bad things associated with that, including the murdering of six million Jewish people, not to mention all of the other stuff. Then ask yourself the question if the world had taken Hitler out before any of that stuff would have happened and you would have asked the same question, "What have we gained"? Iran threatened world peace. They were trying to obtain nuclear missiles and the ballistic missiles to carry them anywhere in the world. They chanted, "Death to Israel" and "Death to America". It was better to take them out now than to wait until they were an "imminent" threat.