Now they have nukes and the aid is cut off. Your argument conflicts with reality.
We know more about nukes than any other country.
Nukes can be very nice, warm & fuzzy,tactical weapons, when applied judiciously.We have a rather large amount of them ourselves.We would like to get rid of them, gradually, as they are just not environmentally friendly overall, but "fear" of nukes is not a factually correct statement in this instance.
During the Cold War MAD standoff with the (former) USSR, I can assure you, nukes were not really the primary deterrant, as mutually assured destruction was, well, assured.ICBMs, Aircraft delivered,and Submarine launched nuclear missiles were and continue to be in the USA, and the worlds arsenal.
The USSR was quite sure the USA would implement a massive MAD responce if attacked with nukes, or actually any WMD.They were entirely correct in their estimation of our resolve.But they were also the other big player at the time, and they also knew the USA would never actually lead an assault against them, or any other nation, with WMD.
The pesky little dictator led superpower wannabe's with small nuclear arsenals,are not, and should not, be accorded the same level of respect, not to be confused with fear.
I am certain the USA does not actually want to completely destroy North Korea.I am also certain we will, if we think it neccessary.
China better get a grip on her pawn,as it has overstepped its authority, and let its mouth overload its ass.
Obviously, this is not the actual ongoing diplomatic chatter, just an educated personal opinion of the situation, from a former Cold War veteran. ;^)