They do decay, not in the inverse square, but they do decay. They also disperse. And as an electronic wave they get beat up by the ionosphere. The high altitude kill America EMP threat is pure lying fear mongering fantasy fiction BS. Period.
Friend, I’m simply sharing facts where you are in error. I’m not arguing with you. The ionosphere has no impact on an EMP - the EMP is generated well below the ionosphere. A nuclear blast at high-altitude has a profound effect on the ionosphere though - but it has nothing to do with an EMP.
“The high altitude kill America EMP threat is pure lying fear mongering fantasy fiction BS. Period.”
It is not “pure lying fear mongering”. There are a lot of unknowns - and the impact of an EMP on modern infrastructure and electronics is unknown. I do not comment on “casualty” guesses - I’m simply stating facts and highlighting gaps in present understanding.