This essay briefly reviews what North Korea’s nuclear capabilities are and shows how
technical capabilities and political intent were inextricably intertwined in shaping the program. The essay then turns to Scott Sagan’s theoretical framework of three models for the bomb to show how Pyongyang’s deep security fears, augmented by domestic and diplomatic drivers, have dominated its decision to build and keep the bomb. The essay concludes with lessons learned from North Korea for the nonproliferation regime.