“How the hell has North Korea managed to build a massive military stockpile?”
About the best timeline of this is at this site:
There are some points left out though. Bill Clinton in the early 90’s shipped a number of supercomputers to North Korean so they could generate power to aide in their agricultural programs. The machines were up graded from the ability to enrich industrial capacity to weapons grade.
The genesis of that was Clinton changing the authority over duel-use technology from the State Dept. to the Commerce Dept. That policy change also allowed Hughes and Loral to give the Chi-coms state secrets regarding their second-stage rocket blowups and some mirv technology. I will never understand why Billy-boy was never charged for treason (aiding and abetting the enemy). At the very least, he should have been impeached for blatantly accepting donations from China through Riady of the Lippo Group and Huang the WH connection. This is all fact and documented.
Although China became a nuclear power sooner than if Clinton had not done that, at least they have become more reasonable over the years. I attribute that to re-acquiring Hong Kong and experiencing the benefits of capitalism. The pseudo spiritual dynasty in Korea has not learned. The Norks are much like imperial Japan when they believed their emperor was a god...and you know the result of that.