The latest North Korean missile test has added new urgency to the problem of North Korea. And the allies have no answer and the tensions between them are likely to grow.

Newly elected South Korean president Moon Jae-in made his first visit to Washington last week. Both sides downplayed the potential tension from the meeting with President Donald Trump. Moon hails from the left and mixes skepticism of the THAAD antimissile system with support for dialogue with the North.

Since taking office the South Korean leader has tried to minimize perceived differences with America, claiming that his views are consistent with President Trump’s policy of “maximum pressure and maximum engagement.” They are, in a “depends upon what your definition of ‘is’ is” sense. Moon opposed U.S.-backed military rule and served as chief of staff to President Roh Moo-hyun, a critic of the alliance and avid supporter of the so-called Sunshine Policy toward North Korea. Although Moon pragmatically tempered his views during the recent election campaign, in philosophy and temperament he could not be further from America’s chief executive.

Indeed, President Trump reportedly was angered by Moon’s criticism of THAAD, which the former declared warranted a billion-dollar payment to America. Worse, administration officials repeatedly suggested the possibility of military strikes on North Korea, anathema to many South Koreans, who would do most of the dying in any new war. Yet the day before President Moon’s arrival National Security Adviser H. R. McMaster confirmed that military options were being prepared for the president.

The central challenge for the alliance is North Korea, which has continued to pursue ever longer-range missiles and more sophisticated nuclear weapons. Unfortunately, Washington and Seoul are bereft of useful ideas on how to halt Pyongyang’s activities, let alone convince the Democratic People’s Republic of Korea (DPRK) to disarm. None of the usual approaches have much chance of success.

Certainly not negotiation. I visited Pyongyang last month. Officials reaffirmed what long has been obvious: the DPRK does not intend to yield its nuclear weapons. North Koreans blamed America’s “hostile policy,” including “military threats and nuclear threats.” They said the North had “become a military power” and promised to match “nuke with nuke.” There was not the slightest hint that the North might be willing to bargain away the weapons assembled at great cost and risk.

No doubt North Korea has multiple reasons for acquiring nukes. They provide the regime with international status, create a useful tool for extortion and cement military loyalty to the Kim dynasty. Still, the impassioned claim of self-defense that I heard resonated. North Koreans complained that they had faced American nuclear threats going back to the 1950s, noted Washington’s penchant for regime change and cited ongoing threats, which included bomber overflights and annual military exercises.

Of course, this account ignores Pyongyang’s behavior. Nevertheless, given the fate of Muammar el-Qaddafi, Kim Jong-un would be foolish to rely on Secretary Rex Tillerson’s assurances that the Trump administration does not seek regime change. Certainly some Americans do, and even the secretary’s opinion could conveniently change once the DPRK had disarmed.

What if America’s “hostile policy” ended, I asked? The North would consider joining the other nuclear powers if they yielded their nukes as well, I was told. Alas, the lion is not yet prepared to lie down with the lamb in Northeast Asia or anywhere else in the world, so the mass renunciation of nuclear weapons seems a remote possibility at best. If there are going to be talks involving Pyongyang, they aren’t going to be over denuclearization. They certainly won’t begin with a North Korean commitment to disarm.

Military action isn’t a viable option either. Sen. Lindsey Graham felt reassured since, as he told NBC: “It would be terrible but the war would be over [there], wouldn’t be here.” The conflict would not “hit America.” In fact, the United States would be involved, and the casualties almost certainly would be high. Moreover, the war would “hit” South Korea very hard—likely leaving the capital of Seoul in ruins. Washington has spent sixty-four years keeping the peace on the Korean Peninsula. Military strikes would be a wild gamble with almost certain catastrophic results.

Nor are sanctions likely to do the trick. China isn’t prepared to join in, since the United States has yet to give Beijing a convincing reason to effectively hand over its one ally in East Asia. Anyway, the North Koreans told me they would stand firm whatever the cost, which seems likely given past behavior.

A North Korean collapse would create its own set of international dangers. And the regime might resist and survive. A half million or more dead from starvation in the late 1990s didn’t cause the current ruler’s father to change course.

Which leaves the United States and South Korea without options, other than to confront a growing North Korean nuclear threat. Once the DPRK develops a reasonably accurate intercontinental ballistic missile, the United States will have to recognize that it is risking Los Angeles, Seattle and perhaps much more to protect Seoul. America’s defense of the prosperous and populous South, which is well able to protect itself, will then endanger vital U.S. interests, e.g. national survival. At that point the alliance could dissolve.

Washington and Seoul must consider acknowledging the reality of the North’s nuclear status and seek a deal freezing the DPRK’s missile and nuclear programs. Accepting Pyongyang’s existing weapons would be far from ideal, but worse would be allowing the perfect to be the enemy of the good. The United States and allied states can manage a world in which North Korea has twenty nuclear weapons and limited delivery options. If the latter’s arsenal expands to, say, one hundred, along with the range of its missiles, and the North’s potential for harm will have grown exponentially.

Offering to freeze annual military exercises, previously suggested by the DPRK, is one option. Proposing negotiations over a peace treaty and phased withdrawal of U.S. military forces from the South is another. Halting North Korean missile and nuclear development is worth paying a significant price.

Along the way the allies should explore what Beijing would require to take a more active role, risking its relationship with the North by threatening tough sanctions to achieve denuclearization. Winning China’s support would intensify pressure on Pyongyang to negotiate. But the PRC’s backing won’t come free and will require serious negotiation, not endless complaining.

There are no good options in dealing with DPRK. War should be off the table. More sanctions are worth a try only if China is all in. If not, negotiations based on nuclear disarmament are a nonstarter. This suggests that the United States must set more modest objectives while looking toward a longer-term transformation of the North Korean state. Such an agenda might not make for pleasant conversation at the summit. But the sooner the allies face nuclear reality in Northeast Asia, the better.