You think that would stop the US war machine from turning the entire Middle East into a giant glass parking lot after a nuke strike on US soil? They don't think that either.
Sadly, I do. Consider Afghanistan and Saudi Arabia. We knew the attacks of 9/11 came from those places. Yet, they are not glass parking lots...
I agree. Nuclear retaliation is highly unlikely in today's world. The operative word being "retaliation".