The world had high hopes for the outcome of the second summit between US President Donald Trump and North Korean leader Kim Jong-un in Hanoi on 27 and 28 February. The possibility of a breakthrough was overstated ^[1] and now we’ve been burned by the irrational exuberance about a North Korea willing to denuclearise. It never planned to do that.

The summit came to a crashing halt on the 28th when the two leaders turned their backs on each other, and on a rather nice lunch ^[2]. At the post-summit press conference, Trump said ^[3] that ‘sometimes you have to walk’, reasoning that the US couldn’t agree to a deal that involved a complete lifting of US economic sanctions in return for North Korea’s dismantling of its Yongbyon nuclear facility. That would have left much of North Korea’s nuclear infrastructure intact—including the undeclared facilities that have been discovered since the 2018 Trump–Kim summit—and would have meant that the US would, in effect, have been subsidising ^[4] the further development of Pyongyang’s nuclear arsenal.

The North Korean riposte ^[5] came later that evening, with a claim by Foreign Minister Ri Yong-ho that North Korea only called for a partial lifting of sanctions in return for the dismantling of Yongbyon under the gaze of US inspectors. A North Korean official also suggested ^[6] that Kim ‘may have lost the will for further negotiation’.

All the signs out of Hanoi suggest that the future of diplomacy between Trump and Kim is uncertain at best. There might be lower level talks between the US and North Korea, but it’s not likely that they would lead to a resolution that satisfies all parties. The North Koreans are also watching Trump’s growing domestic woes, including the testimony ^[7] by his former lawyer, Michael Cohen—which burst political bombshells all over Capitol Hill as the Hanoi summit was getting underway—and the impending release ^[8] of the Mueller report.

So where to from here?

According to Trump, Kim has promised ^[9] not to conduct further missile or nuclear tests. That may hold for the time being, but if the North Koreans decide that there’s an impasse or that domestic US politics have undermined the ability of the US to deliver on any deal, it would be quite easy for Kim to reverse course. It just takes a phone call, after all, to order a new missile test, or even a nuclear test.

The rationale for further testing could be tied to a perceived need to perfect long-range missile systems, including getting more data on warhead designs to ensure a future nuclear-armed North Korean ICBM can accurately deliver a warhead on a target. And the North Koreans have talked about a ‘Juche Bird ^[10]’ nuclear test involving an atmospheric nuclear detonation.

Despite Trump and Secretary of State Mike Pompeo putting a positive spin in the post-summit press conference about future opportunities for diplomacy, there’s broad consensus in the US intelligence community—notably highlighted in a recent assessment ^[11] by Director of National Intelligence Daniel R. Coats—that North Korea won’t denuclearise, at least not in the way the US seems to interpret that term.

The Trump administration must therefore address a fundamental dilemma. Washington’s stated policy of seeking North Korean denuclearisation is based on a false assumption that Pyongyang will give up its nuclear weapons if it’s offered the right inducements. But if Kim is determined to hang onto nuclear weapons no matter what, then the US policy must reinforce deterrence.

That means that the US should avoid making further concessions, such as signing a peace treaty—a move supported by South Korea ^[12]. A peace treaty raises the risk that Kim could put new demands on the table. For example, North Korea could challenge ^[13] the continued presence of US military forces and the United Nations Command on the Korean peninsula, or even the continued provision of extended nuclear deterrence security guarantees to South Korea and Japan.

The North Korean definition ^[14] of denuclearisation of the Korean peninsula broadly focuses on the presence of US nuclear and nuclear-capable forces around the peninsula rather than Pyongyang eliminating its nukes. That interpretation has been reinforced by North Korea’s recent raising of the prospect of links ^[15] between progress towards denuclearisation on the Korean peninsula and Japan’s potential for an independent nuclear deterrent capability.

The expectation that North Korea will agree to final fully verifiable denuclearisation (FFVD ^[16]) needs to be hosed down. Diplomacy can and should certainly play a continuing role in getting a meeting of minds to address the drivers of tension, and it can play a useful role in working on confidence-building measures to reduce the potential for misunderstandings or lower the risk of sliding back to the ‘fire and fury’ type tensions last seen in 2017. But the US shouldn’t proceed with further diplomacy with the expectation of convincing Kim to give up his nukes.

Above all, the emphasis in any future talks should be on ensuring that the North Koreans are not tempted to go back to more missile and nuclear testing. Such a development would certainly precipitate a slide back to pre-war tensions and the prospect of a major military crisis on the Korean peninsula.

To prevent such an outcome, the US must seek to boost deterrence against Pyongyang and increase dialogue with Seoul and Tokyo, to reassure them of the stability of alliance agreements.

That’s now a real challenge given Trump’s wrecking-ball approach to US alliances. Even as the Hanoi summit ended, he couldn’t resist challenging the value ^[17] of US – South Korea military exercises—and then cancelled ^[18] the major Foal Eagle and Key Resolve exercises. That’s not the best signal to send to a key ally as concerns grow that further tensions between Pyongyang and Washington may be on the horizon. The Japanese will take note—and so should Canberra.