Since Donald Trump took office, the growth of North Korea’s nuclear arsenal and the increasing capability and diversity of its ballistic missile force have made that country the most urgent threat to U.S. national security. Observers as diverse as Mark Bowden in the Atlantic, Michael Auslin of the Hoover Institution, and former White House chief strategist Steve Bannon agree that all military options available to the president are bad. How exactly did we get to this point? What policy decisions led to an emerging intercontinental ballistic missile capability and a nuclear arsenal that could rival that of the U.K. by the middle of the next decade? How did we end up with a North Korean leader seemingly more willing to run enormous risks than his father or grandfather? The answer demonstrates once again the venerable adage that “the road to hell is paved with good intentions.” One of the few national figures who consistently raised alarms about U.S policy towards North Korea was former vice president Dick Cheney, and he has proven prescient. The United States now faces the real prospect of a war that Secretary of Defense James Mattis says would be “catastrophic.” This story should be studied carefully before it repeats itself—say, in Iran.

Kim Il-sung manifested an interest in obtaining nuclear weapons almost as soon as he founded the North Korean ruling dynasty, in the early 1950s. His Soviet patrons were not prepared to oblige but did help to build a nuclear research reactor in Yongbyon that could provide a source of plutonium. His unrequited urge for nuclear weapons led Kim to approach Mao Zedong after the successful Chinese nuclear test in 1964, but he was again turned down. Ultimately Moscow, wanting to keep the number of nuclear-weapon states low, persuaded Pyongyang to sign the Nuclear Nonproliferation Treaty in 1985. But North Korea procrastinated about signing the mandatory safeguards agreement to give the International Atomic Energy Agency access to the Yongbyon reactor and other nuclear facilities while quickly initiating a clandestine program to reprocess fissile material for its nuclear arsenal. The loss of its superpower patron after the collapse of the Soviet Union made nuclear weapons a matter of some urgency for the Kim dynasty. Thus began a pattern of serial prevarication and the use of “arms-control” negotiations as a cover for covert activity.