The nuke part is optional, see: https://en.wikipedia.org/wiki/Counter-electronics_High_Power_Microwave_Advanced_Missile_Project https://en.wikipedia.org/wiki/C

The nuke part is optional, see: https://en.wikipedia.org/wiki/Counter-electronics_High_Power_Microwave_Advanced_Missile_Project https://en.wikipedia.org/wiki/Counter-electronics_High_Power... that said, there have been multiple past nuclear EMP orientated tests: https://en.wikipedia.org/wiki/Nuclear_electromagnetic_pulse https://en.wikipedia.org/wiki/Nuclear_electromagnetic_pulse results vary by location (earth's mag field) and pre hardening of infrastructure.