The central foreign policy crisis for the United States right now is that North Korea is soon expected to be able to strike an American city with an inter-continental ballistic missile (ICBM). This situation is certainly grave — but it is by no means unique. During the Cold War, the United States lived with the Soviet Union, a country whose nuclear arsenal dwarfed that of present-day North Korea, as well as China, a nuclear state ruled by a dictator (Mao Zedong) frequently considered unstable.

So why does today's North Korea threat seem so unacceptable to the U.S. government? In short: Why can't we live with a nuclear North Korea?

John Park, Asia security analyst at Harvard's Kennedy School of Government, explains the logic:

"[The U.S. government thinks] Kim Jong Un equals irrational plus undeterrable plus revisionist plus commercial," Park said during a panel discussion at Asia Society on Thursday. Because the U.S. believes that Kim is "literally crazy," Park said, they can't be certain he won't sacrifice his life or his country's viability for the opportunity to strike the United States. This makes him undeterrable — "a millennial with nuclear ICBMs," Park explained.

Should Washington acquiesce to Kim and allow North Korea to continue its nuclear programs, Park said, its problems with Pyongyang won't just go away. For instance, there would remain the possibility that North Korea would sell its nuclear technology to regimes, such as Iran, inimical to the United States. 

As Park explained, this view is hardly the consensus among North Korea experts in the United States but appears to be the prevailing view within the Trump administration. 

Park spoke about North Korea along with Michael Swaine, senior fellow at the Carnegie Endowment for International Peace, and Asia Society Diplomat in Residence Daniel Russel. The complete video from Thursday's program can be found below: