the more reason to not start a war with Iran
If a belligerent alcoholic threatens to assault someone at a bar, do you not call in the law enforcement agents because he MIGHT hurt somebody? No, you deal with the threat. You don't let a belligerent asshole be a belligerent asshole just because he has a few muscles. If he says he's going to hurt somebody, you take the threat seriously and make sure you take the necessary steps to prevent him from hurting somebody. You obviously don't confront him yourself, but you make sure that the people equipped to confront him do so.
In case you had trouble with the analogy, Iran is the belligerent asshole and the relevant authorities are the allied forces.