The North Korean elites might willingly sacrifice half of their population in a war of their choosing, since almost half of population of North Korea is in the military.
Videos of their military parades show a hoard of malnourished, brainwashed, young (and old) conscripts.
This chart, which shows military strenght comparisons to the US and other nations is troubling.
If the idiots that are feeding NK would cut off the food supply then NK would shrink in size. Attrition is effective.