Negotiations to control and perhaps eliminate North Korea's weapons of mass destruction (WMD) appeared to achieve positive results in the 1990s. But these positive trends reversed direction in 2001–2004 under President George W. Bush. Why? This essay weighs six possible explanations. 1. progress in the 1990s as a mirage; 2. cultural differences; 3. distrust of international agreements; 4. perceptions regarding the utility of WMD; 5. internal divisions within each government and society; and 6. ulterior motives.The evidence suggests that the sixth explanation carries the most weight. Top leaders in the Democratic People's Republic of Korea (DPRK) as well as in the United States had priorities other than arms control. Each side used arms control negotiations as an instrument to promote its political and economic agenda in other realms. Pyongyang demanded large and certain rewards to give up its main bargaining chips. North Korea's negotiating behavior suggested some willingness to freeze or eliminate WMD programs if the price were right. But Kim Jong Il's regime clearly saw its nuclear and missile capabilities as major assets not to be traded away except for very substantial security and economic rewards. For its part, the Bush White House probably worried that any accord with Pyongyang would impede Washington's larger political, military, and economic ambitions, including deployment of a national missile defense (NMD). There was also a subjective element: President Bush probably loathed Kim Jong Il and did not relish the prospect of making any compromises with evil incarnate. For enlightened self-interest to prevail, the parties could benefit from greater empathy and a quest for mutual rather than one-sided gain.