I think the Iranian fleet would sink before they got close enough to launch an EMP.
Iran is building missile sites in Valenzuela which will put the eastern half of the US within range.
They’ve also orbited a 60kg payload, which would allow them to put that 60kg anywhere they want.
In the book “Lights Out”, a Saudi king uses one of his super tankers, fills it with sand so it appears it is full of crude oil heading to the US for a scheduled delivery. He has two scuds on board. When the tanker gets off the coast of the US, they erect the missles launchers and send off 2 scuds to be detonated 300 miles above the US to set a major EMP in motion. The tanker is scuddled (sank) by the crew shortly after. If that played out..even if our subs counter-attacked, what good would it do us ? And without proof of the tanker, who would we go after? Instant 1800s. But that could never happen to us, could it ? Sheriff Joe Biden or maybe FEMA would take care of us...LOL. It’s going to take a good 15 years to replace the World Trade Centers. What would it take to correct a national disaster?
Why do you think they would send a fleet?
It would only 1 missle.
It would be launched from a single small freighter or fishing boat 200 miles out to sea from the east coast.
Then BAM, instant stone age!
They wouldn't need to send ANY Iranian ships for the purpose. An old junky freighter could do the job.
As far as retaliation is concerned, sure, our military, not in this country would be available for the job. The damage would still be done to this country, with regards to all things electric, or electronic. Folks wouldn't be able to survive without the steady flow of food from the trucks and trains that carry them across the country on a daily basis.