Many people are unaware that a nuclear weapon detonated above the atmosphere can have an impact similar to a CME. Indeed, since the spectrum of radiation is broader the phenomenon is more complex and impacts a much wider category of electronic devices.

My conjecture is that President Trump changed his tune on "rocket man" when he learned that North Korea did not need accurate missiles with reentry vehicles to send the US back to the pre-electronic age.

Geognosticator