This is a problem for any solution to the North Korea nuclear issue that leaves North Korea with any nukes or nuclear technology
Syria has repeatedly used chemical weapons for large-scale assaults on its own citizens. North Korea has been instrumental in helping develop those weapons, despite numerous sanctions. Without being put in check, North Korea’s current regime, led by Kim Jong Un, will likely continue this behavior.
And don't forget that North Korea was helping Syria build a secret nuclear reactor before Israel destroyed it with an air strike not long before the current Syrian multi-war erupted.
North Korea sells conventional weapons and provides support for chemical weapons and nuclear technology. Why wouldn't North Korea sell nukes to their partner Iran?
Which is why in many ways our North Korea problem is actually an Iran problem:
I've long felt that in a bilateral framework, we could deter North Korea's nuclear weapons. ...
Maintaining their power is the ultimate goal of North Korea's ruling class. So a nuclear armed North Korea is admittedly far more dangerous on a wider front (including America eventually), but can be deterred.
As a bilateral issue.
The problem with accepting North Korea's nuclear power status is that Iran could purchase nuclear weapons from North Korea.
As long as nutball Iran can buy North Korean nukes, it isn't safe to rely on deterring North Korea armed with nukes because the main threat from North Korean nukes would be those sold to Iran.
Only the elimination of North Korea's most dangerous potential customer for nuclear weapons, Iran controlled by the Shia Islamist mullahs, can make it possible to adopt a policy of deterring North Korea through our own nukes (including most likely South Korean and Japanese nukes because neither could be 100% sure we'd risk a nuclear attack on one of our cities if North Korea nukes Seoul or Tokyo) and missile defenses.