"Suppose they launch it and it does no damage," he posited. "What do we do then? No one is asking that."
I strongly suspect that massive retaliation would be under way before the damage had been assessed, not that it is going to help anyone else in the world (least of all those moderately close to NK).
The issues here of power grid resilience to major country-wide effects though are something the whole world should be considering, not just the fast EMP effects on electronics, but rather that risk of a solar flare causing extensive power grid damage. It would only take a couple of days without fresh water, sewage disposal, or fuel pumping for food delivery to seriously cripple any nation for decades.