The problem is not A country with an ICBM, but A country led by a violent wack job who murders his relatives with anti-aircraft guns and chemical weapons with an ICBM. And if the theory of EMPs works out, and he has threatened an EMP against the US, 90% of the North America could effectively be wiped out with one missile.
If Kim Jong Un wants to commit suicide, he's more than welcome to launch a missile at the US. I think he'd rather live. It's all sabre-rattling. I'd rather they not have nukes, but it's far too late now to do anything about it that won't end in fullscale war.