I agree with ksst. If someone says they are going to punch you in the mouth you can just walk away. Of course, this situation isn't really about a schoolyard fight. It's about international incidents which can lead to war, billions (trillions) spent, and thousands (or millions)killed. It's one thing to get huffy with someone at the bar and get in a fight. It's quite another to let another country's name calling bullshit goad us into the kind of actions that can't be undone. It's not even apples and oranges, it's apples and spaceships.
And I still don't understand why you would threaten your nephew over something Iran did.