It's really a terrible situation, and I agree there's no way this is going to end well. Nuking NK will mean at best, an environmental and humanitarian disaster

It's really a terrible situation, and I agree there's no way this is going to end well. Nuking NK will mean at best, an environmental and humanitarian disaster on scale we can't even comprehend, and at worse a full on nuclear exchange between the US and anyone who decides to retaliate which could realistically be one or both of China and Russia. The alternatives suck as well; try and take out JUST NK's nuclear capability, and hope that it works and that they don't retaliate by obliterating Seoul. Or try and decapitate the regime, hope it works, hope you don't miss anyone, and hope someone worse doesn't come to power. If the world lets them go and keep their nukes, what happens then? Would anyone stop them from invading the South if there was a risk of NK going nuclear in response?