It is common for movie critics to say that the sequel is not as good as the original. And many diplomatic critics will judge that second installment of the Donald Trump and Kim Jong Un widescreen bromance fell short of expectations.
Having failed to produce any agreement, the Hanoi summit did not even exceed the low bar set by the Singapore summit, which at least produced some common commitments and a specific deal on the return of the remains of Korean War American soldiers.
But that does not mean the Hanoi summit cannot contribute to progress between the United States and North Korea. Here are some of the impacts of "no-deal" summit for U.S.-North Korea relations and for the region.
First, the Hanoi no-deal summit was necessary to combat fears that the U.S. president faced so many difficulties at home that he would be tempted to make a bad deal. By walking out on North Korean leader Kim Jong Un, Trump was able to project strength; if Trump had made a bad deal with Kim, the deal would have been challenged as further evidence of Trump's weakness.
Moreover, the perception that Kim Jong Un had tried to evade working-level talks by escalating every issue to Trump further reinforced the need for Trump to show that he could walk away. It also sent a signal to North Korea that the establishment of an effective working-level channel will be an essential element in overcoming hostility between Washington and Pyongyang.
Second, the Hanoi no-deal summit imposed transparency on the gaps that divide the U.S. and North Korea. If the two sides had made a limited deal on the key issue of North Korea's nuclear program, some underlying gaps over questions such as the scope of denuclearization and the scope of the lifting of the economic sanctions imposed on Pyongyang could have been papered over.
But this would only have triggered a breakdown at a later stage in the negotiations. The U.S. rightly continues to demand that North Korea take actions above and beyond dismantling the Yongbyon nuclear complex that is the biggest site in its program. Washington is correct to be concerned about other secret locations identified by intelligence work. Unless these sites are included, North Korea's denuclearization will be incomplete.
Trump's approach indicates the seriousness of his purpose regarding denuclearization. North Korea, for its part, insists that it must see substantial reductions in sanctions to justify closing sites beyond Yongbyon, not to mention destroying its existing arsenal of missiles and warheads. These negotiations over pace and price can be bridged only through additional diplomatic efforts.
Third, the Hanoi no-deal summit will inhibit efforts by South Korean president Moon Jae-in to move inter-Korean relations forward, but it will also mobilize efforts by South Korea to help the United States and North Korea to bridge the gap on denuclearization and sanctions-lifting. Efforts to restart working-level talks between the United States and North Korea may benefit from background conversations by South Korean interlocutors that can help Washington and Pyongyang to understand the gaps between the two sides and ways to resolve them. Seoul must step up its efforts to support peaceful denuclearization of North Korea.
Fourth, the Hanoi no-deal summit generates greater pressure on China from both sides as the United States expects Beijing to continue the sanctions pressure while North Korea seeks relief from sanctions, before Washington is willing to advance a peace-and-denuclearization process in which China will be a primary beneficiary.
For Tokyo, the Hanoi no-deal summit comes as a relief, given concerns prior to the summit that Trump might sell-off his allies' interests, if only to justify an apparent request to Prime Minister Shinzo Abe to nominate Trump for a Nobel Peace Prize. The no-deal summit puts off the prospect of a Nobel Peace Prize for now, while holding out such a hope if indeed peace-and-denuclearization can be achieved in the future. A credible process involving tangible trade-offs between the United States and North Korea will be necessary before such a goal can be achieved.
The Singapore summit yielded a modest agreement, but did not achieve an effective working-level process for achieving transformation of the U.S.-North Korea relationship in exchange for complete denuclearization. By exposing the gaps between the two sides rather than papering them over, it is possible that the Hanoi summit failure could be used to jump-start the working-level processes that must accompany summitry. Trump and Kim may have fallen in love, but the Hanoi break up can help to determine whether this was just a fling or can lead to a lasting change in the relationship between the two countries. All eyes are on the next installment of this high-stakes drama.
Scott Snyder is senior fellow for Korea studies at the Council on Foreign Relations and the author of "South Korea at the Crossroads: Autonomy and Alliance in an Era of Rival Powers."