Iran will be able to make few nukes compared to the west. If Iran used them, there would be little left of Iran, and most of the West will be untouched.
The mullahs may be unpleasant people, but they are not mad.
Seems Trump is not the only western person that loses their common sense when it comes to the M E.
PS, even if they used a dirty bomb in a western city, the origin can, I believe, be ascertained by the scientists, and if from Iran see my first sentence.
Let's not forget that Iran isn't the only non western country to have nukes.