Will Iran do it?

"Indeed, Iran has practiced ship-launched EMP attacks using Scud missiles--which are in the possession of scores of nations and even terrorist groups. An EMP attack launched off a ship, since Scuds are common-place and a warhead detonated in outer space would leave no bomb debris for forensic analysis, could enable rogue states or terrorists to destroy U.S. critical infrastructures and kill millions of Americans anonymously."

https://www.congress.gov/event/113th-congress/house-event/LC25001/text