the thing is most countries are not EMP protected cause its reletively new weapon (not the theory but the practical side).
Originally posted by WestPoint23
Yeah but an EMP device that can take out the whole US is still many many years in the future
High-altitude nuclear detonations, above 40,000 meters, produce beautiful auroral displays, but the effect on communications and power facilities can be quite ugly over an entire continent. A nuclear detonation over centrally located Kansas City or Omaha at a height of 500 km would illuminate the entire United States with an EMP field of 25-50 kV/m, which could cause damage to electrical and electronic systems at any point in the US.