Don't know about a law, but there's plenty of empirical evidence that you're broadly right, it is I suspect what the Epstein class are counting on in the US - they'll come out unscathed and the masses will wear the impact.

I did pick North Korea for a reason though - they have an economy with very limited reliance on even China and Russia and have basically spent 70 years preparing for this. I genuinely can't think of a country less likely to be directly affected. Second order impacts such as say Russian (or even Chinese) rogue military units seizing areas and pillaging are possible, but even then they are already at subsistence level in the main, so impact should be minimal.

It will be poor countries like Bangladesh who rely on selling sweatshop clothing into the developed economies that will be in the biggest trouble - exports will be decimated and they are already on the breadline.