Reinhold Neibuhr, the great American theologian and philosopher, often urged Americans to seek “proximate solutions to insoluble problems.” That’s sound advice for the current situation. Denuclearization of the North will not be possible to achieve, if it is possible to achieve at all, unless there is a transformational change in North Korea’s relationships with the United States and South Korea. It remains to be seen what kind of constraints Kim might be willing to accept on his missile and nuclear programs and what he will expect in return once he attains credible ICBM capability. The only way to find out is in direct talks between the United States and North Korea. In the meantime, the United States will have to live with a nuclear-armed North Korea and rely on deterrence and defense to contain the growth of its missile and nuclear capabilities.

More fundamentally, this posture will only be sustainable and effective in preventing war, especially as a result of miscalculation, if Pyongyang clearly understands, with no shred of ambiguity or uncertainty, what behaviors the United States can accept and what North Korean actions would trigger a catastrophically devastating American response. The three most important of these are: a North Korean nuclear, biological or chemical (NBC) attack against the United States, South Korea or Japan; a North Korean invasion of or other significant military attacks against South Korea; and North Korea’s sale, export or transfer of any NBC weapons, material, equipment, or technology to a terrorist organization or a state sponsor of terrorism. These are the rules of the road that the United States and North Korea will need to live by if there’s to be any hope of avoiding a catastrophic confrontation on the Korean Peninsula and beyond.

Aaron David Miller is a vice president and Distinguished Fellow at the Woodrow Wilson International Center for Scholars and author of The End of Greatness: Why America Can’t Have (and Doesn’t Want) Another Great President. Miller was a Middle East negotiator in Democratic and Republican administrations.

Richard Sokolsky is a nonresident senior fellow at the Carnegie Endowment for International Peace. He served in the State Department for thirty-seven years, including ten as a member of the secretary of state’s Office of Policy Planning from 2005 to 2015.

Image: One of two U.S. Air Force B-1B Lancer bombers receives fuel from a KC-135 Stratotanker while flying a 10-hour mission from Andersen Air Force Base, Guam, into Japanese airspace and over the Korean Peninsula, July 30, 2017. U.S. Air Force photo/Staff Sgt. Joshua Smoot/Handout via REUTERS