From what I have read, Kim Jong (Sr) allowed inspectors into his country in 1992, under the leadership of Hans Blix, also noted to be involved with the Iraqi fiasco,. It was said at that time that NK had attempted to reprocess plutonium, and when the IAEA asked to see other "waste" sites, NK balked and sent them home.
In 1993, NK was going to withdraw from the Non-Proliferation Treaty (NPT) unless the US gave into their demands which included grain and two light water reactors.
In 1994, President Clinto sent in Jimmy Carter, whom the NK leader called a "man of justice" to do a little bargaining as a private citizen. In June of 1994, Carter wooed the NK leader and dropped demands for the Un inspections, but asked for them to return their spent fuel rods.
In July of 1994m Clinton an "Aggreed Framework" with North Korea, and their new leader, Kim Jung Il. This agreement gave NK more nulcear power stations if they promised to give up pursuing a nulcear bomb. Clinton also promised them 500,000 metric tons of fuel oil annaually as well as grain, in a return for a promise to "freeze" their nuclear ambitions.
This food went to feed the NK Army, and did not go to the people of North Korea.
In 1997 Madeline Albright shrugged off concerns of North Korea bragging about the Framework Agreement as being one fo the "best things the Clinton administration has done to stop nuclear weapons in North Korea". yeah right.
In 1998, NK launched their first three stage rockect, the Taepo Dong-1, capable of reaching Japan and nearly to Alaska.
In June of 2000, Japanese and Chinese were able to confrim that an underground uranium processing plant was located in Chuma, NK.
It looks to me like actions by Clinton and his envoy Jimmy Carter allowed this proliferation to take place under their watch and in many ways contributed to it.