In January North Korea conducted its fourth nuclear test in the face of universal international protest. Even China, Pyongyang’s one nominal ally, joined in the criticism.

With Beijing’s support the United Nations imposed new sanctions on the Democratic People’s Republic of Korea. The U.S. and its allies warned Pyongyang of further isolation if the DPRK continued to flout the will of the international community.

Now the North appears to be preparing another nuclear test. If the DPRK does so no further proof will be needed that the North intends to become a significant nuclear power.

Pyongyang has invested too much to drop the program. Moreover, the North lives the old Henry Kissinger aphorism that even paranoids have enemies. The U.S., backed by the Europeans, has demonstrated its willingness to oust dictators on its “bad” list, even after making a deal with them, such as Moammar Khadafy.

What makes the prospect of another test particularly dramatic is Kim Jong-un’s apparent willingness to proceed at any cost. He can have little doubt that the U.S. will press for additional sanctions. He knows that no other government will defend his regime.

He is aware that after the January test the People’s Republic of China approved tougher international penalties. Every additional DPRK provocation threatens to become the last back-breaking straw for China, leading it to target food and energy aid, which would cause Pyongyang enormous hardship.

What to do when nothing so far has worked?

First, the U.S., Republic of Korea, and Japan should consider how to deal with a nuclear North Korea. Two decades of pronouncements that the North must not develop nuclear weapons are for naught.

If North Korea continues to augment its capabilities, then what? What military, political, and economic steps should be taken, and by whom? The more likely the prospect of Pyongyang as a modest nuclear power, the more urgent serious thinking about a transformed Northeast Asia.

Second, Japan and the ROK should set aside past differences to confront a common threat. The colonial era ended 71 years ago. These two prosperous democratic countries should prepare for problems of the future rather than reinvigorate hatreds of the past.

Third, U.S. and its allies should further engage Beijing over Pyongyang. The PRC has the most leverage with the North because of the former’s energy and food assistance, but is hesitant to risk encouraging regime collapse. Thus, as I point out in National Interest: “the allies need to offer to share costs, acknowledge Chinese interests, and convince Beijing that they would not take geopolitical advantage of the demise of the PRC’s one East Asian ally.”

Fourth, Washington should offer to defuse the perceived threat environment facing the North, backed by an offer to negotiate on issues other than nuclear weapons. This doesn’t mean blaming America or trusting Pyongyang. Rather, it means recognizing that the current regime has reason to fear the U.S. To the extent that Kim desires a wealthier nation, he might be willing to limit his arms programs if less concerned about his dynasty’s future. Maybe not, but Washington should test the possibility.

Fifth, the allies should consider the advisability of Japan and South Korea developing countervailing nuclear arsenals. America’s nuclear umbrella keeps the U.S. dangerously entangled in a potential conflict no longer critical to American security.

We are approaching a time when Northeast Asia will have three nuclear powers, all potentially bad actors: China, Russia, and the North. Washington can forever remain in the middle of this unstable nuclear scrum. Or America’s democratic allies can deter aggression on their own. The idea certainly is worth discussing, especially within hearing of Chinese officials.

It’s still okay to hope for collapse, implosion, or some other deus ex machina to “solve” the problem of the North. But it is foolish to expect a miraculous rescue. The U.S. and its friends should start planning seriously for a nuclear DPRK.