It must be budget time.
EMPs require a nuclear attack on the US. Anything large enough to knock out the entire nation is not something that would be built in a mountain in Korea. Thus, this type of attack would come from Russia or China. They would be a radioactive heap within half an hour.
Think about this for a minute or two. Ask yourself how we would respond to a nuke attack.
MAD still applies.
If we were talking about a massive Carrington event, it would not take out the the entire country.
“EMPs require a nuclear attack on the US. Anything large enough to knock out the entire nation is not something that would be built in a mountain in Korea. Thus, this type of attack would come from Russia or China”
BTW, the Russians or Chinese could do the same, without launching from their home territory (and, if you think about it, why on Earth WOULD they launch from their home territory unless it was part of a massive 1st strike?).
All that is necessary is a tuned ATOM bomb (not a more sophisticated H-bomb) and a rocket that can reach orbit. Many nations, not just Russia and China, have that capacity, including some rather unfriendly nations.