See 98. Use an EMP weapon to change command and control to consternation and confusion.
Most every important piece of military and national command authority electronic/electrical gear has been EMP hardened. Equipment tests used to take place down along the Chesapeake at Solomons Island, USN facility in Maryland when I was still in DC.
All DoD equipment has to be compliant with the MIL-STD below:
https://nts.com/services/testing/emc/electromagnetic-pulse-testing/
How about they create the Potomac Sea? ;-)