The PRK has us right where they want us. We do not have the military to do what many folks think we should do, and the China/Russia side of the equation makes it even more problematic. PRK can saber rattle all they want and know that we are not really in much of a position to do anything about it. China loves this setup because they can provide PRK with everything they need and let them do the dirty work of messing with the U.S. And dealing with PRK in a conventional sense is not anything like dealing with Muslim fanatics. Yeah, watch Hacksaw Ridge or We Were Soldiers. I spent almost the entire 1970's in uniform myself, and dealing with waves of highly trained folks coming at you with weaponry almost equivalent to that you have, with a zeal to go at it till the last man standing, is a nasty ordeal. High tech can deliver wild kill ratios compared to ones own loses, but when there is an almost unlimited pool of bodies they are willing to throw at you, it isn't as effective as one would like. And while we are expending most of what we have in such a conflict, there would be little left to have an effect on anyone else who wanted to play games with us elsewhere. War isn't Hollywood.
We have extended ourselves to the limit on what we have the capability to do militarily on a conventional level. Even then, the damage PRK could do to us is more than most people realize. If they can get a couple of tipped missiles over the U.S., they could do simple air burst of a couple of nuclear warheads, without even being remotely accurate or damaging much on the ground, but would cripple most to the U.S. due to EMP effect. Most electronics would be fried and the power grid would be shut down. That alone would cause thousands of deaths in short order and hundreds of thousands over the following weeks and months. Much of the country would effectively be back in the stone age. It is common knowledge that grocery warehouses have only a 3-4 day supply for their stores. And all commercial trucks and such have electronic controlled engines just like cars. No truck, no food or medicine. You get the picture. And meanwhile, the powder keg of the Middle East would surely go off at that point. The PRK is the best thing to come along in regards to those that want to do us harm. That is why China and Russia have given them all the stuff PRK has and created a outstanding chess game for them.
About the only real thing we can effectively do in the short term is get a more highly refined and perfected anti-ballistic missile system in place that has an assurance it could take out anything incoming before it can get within range where EMP would be a problem. We have a real nasty mess on our hands.