How far will we go to stop the NORKs?

From getting nukes that is.  They are really really close to having nuclear tipped missiles that can reach the US.  The last test flight showed enough range, and then some, to hit Washington and Boston.  There are reports that the missile broke up on reentry, but they ought to be able to fix that.  Then they need to build a nuke small enough to fit on the rocket, a nose cone that can withstand reentry, and a reliable fuse.  I don't think any of these will take very long to do.  The NORKs could have it all together within a year.  After that, Katy bar the door.
   The NORKs want missiles to keep us from doing regime change on them, the way we did on Saddam Hussein.  As it is, they have enough conventional artillery within range of Seoul to deter damn near anyone, with nukes in their hands, they figure to deter even us.
   And the NORKs are dead set on getting nukes.  I cannot imagine Rocket Man backing off his nuclear program for anything less than the Chinese cutting off all trade with him.  And the Chinese clearly don't want to do this, they like having the NORKs around as a buffer state, and as a semi tame attack dog to let out to bite the Americans every so often.
   We could slap a good stiff trade killing tariff on Chinese exports to the US.  That would hurt China, and it might get them to cut off the NORKs.  The Chinese would not like it but we could do it.  If we have the stones.  Nobody knows if Trump would do this, and if the country and the Congress would back him up if he tried it.  I have not seen any Gallup polling on this subject.
   Or we could try straight forward military action, air strikes followed with ground forces.  This amounts to starting up the Korean War all over again.  Last time was bad.  This time would probably be just as bad.  And the South Koreans would take a lot of damage and casualties, something they certainly are not happy about.
   Or we could do the paper tiger act, keep on snarling at the NORKs but not actually do anything.  This would probably cause the Japanese, the South Koreans, and maybe even Viet Nam and Taiwan to go for their own nukes.  Which is bad, but at least these countries are all US allies or friends.  It would shake up the Chinese though.