You think, North Korea is dirt poor but somehow managed to build an ICBM capable of hitting the US mainland.
To think that China didn’t play a part in that is naive and to think if North Korea has the capability, then Iran probably has the same capability.
My point, is technology can’t be bottled up and kept to 2-3 countries, countries like Pakistan has nuclear weapons, at one time South Africa has nuclear weapons, there is no reason to think North Korea or Iran don’t have the same technology.
There are plenty of real threats facing the US. I would go get an ulcer over one of those and not this thing made up in your brain or implanted there by some rather ill-meaning self-dealing advisors trying to cook up a scheme for making a lot of money advising the US government on schemes to deal with the EMP threat.