The military will use the nukes if necessary, and that use will drown out all complaint from any quarter for a long time to come. Nukes may not be necessary against Iran or N Kor, and permission for gratuitous use will be denied.
Well, suppose the following:
Iran uses a nuke to destroy a US Infantry Brigade stationed in Iraq.
Do you think we could get away with the proper response- namely the anhillation of a large Iranian City?
I sincerely doubt it.