US President Donald Trump and North Korean leader Kim Jong Un will likely be all smiles as they shake hands in Hanoi for a meeting meant to put flesh on what many critics call their frustratingly vague first summit in Singapore. But behind the grins is a swirl of competing goals and fears.
In addition to the two main players, China, South Korea and Japan also have deep interests in what Trump and Kim can hammer out when they meet in Vietnam tonight and tomorrow. The biggest question of them all: Can the United States and North Korea agree on what the "denuclearisation of the Korean Peninsula" means — the wishy-washy language they settled on in Singapore — and, if so, can they create a successful framework that gets it done? Here is a look at the contending goals in a summit meant to settle the world's most vexing nuclear standoff.
If the US position is fairly clear — ridding North Korea of as much of its nuclear programme as possible — it is much less certain how much Kim is willing to relinquish of what his propaganda services call the nation's "treasured sword". Kim is clearly doing something different than his dictator father and grandfather.
In addition to building a nuclear arsenal that commands world attention and working to ensure economic, military and personal security, he's also pushing to lift his nation from poverty.
To do that, he needs to find a way to ease crushing international sanctions so he can pursue engagement projects with South Korea, including two big-ticket ventures to reopen a jointly run industrial park and a tourist resort.
North Korea also has pushed for a peace declaration ending the Korean War, which halted in 1953 with an armistice, not a peace treaty. North Korea may see this declaration, and an eventual peace treaty, as a way to eventually draw down US forces in South Korea and allow the two Koreas to pursue the dream of reunification, on North Korea's terms.
Trump savoured the wall-to-wall coverage of his first summit with Kim last June. But he's under pressure to do better this time.
The US President wants progress on denuclearisation, even as he tries to keep expectations low, saying he has no "pressing time schedule" in mind.
At the Vietnam summit, the US is likely to seek an agreement on how to start work on Kim's previously reported statements that he's ready to dismantle his country's plutonium and uranium enrichment facilities.
Trump wants Kim to formalise his offer to let international experts in to verify dismantling steps at North Korea's main rocket launch site and a nuclear testing site. Trump also would like to get back the remains of more Americans killed during the Korean War and to move toward a permanent peace on the Korean Peninsula. Ultimately, the US also wants an inventory of North Korea's nuclear and ballistic missile facilities, equipment and material, and then an agreed-upon process for destroying them in a way that can be verified. But no one expects the two sides to reach that point in Vietnam.
Seoul has prioritised stabilising its bilateral relationship with North Korea amid the larger nuclear negotiations between the US and the North. It now hopes the second Trump-Kim summit will provide an opportunity to restart inter-Korean economic projects held back by heavy US-led sanctions.
In a recent telephone conversation with Trump, South Korea's President Moon Jae In said Seoul was ready to restart joint economic projects with North Korea and asked Trump to consider offering them as incentives for the North to denuclearise when he meets Kim.
For China, concerns about instability in North Korea, its ostensible communist ally, have long overridden worries about its nuclear arsenal.
Beijing chiefly fears a collapse of the North Korean economy that could lead to armed conflict within the Government and a potential flood of refugees streaming across the rivers that separate the neighbours.
China is North Korea's chief source of assistance and trade, and any movement toward sanctions relief would be warmly welcomed by its business community.
Japan, which is still tormented by kidnappings of its citizens by North Korea decades ago and lies within easy striking distance of the North's missiles, has long wanted a deal.
But not just any accord will do.
There's worry about reports that Trump may seek an agreement that only partially targets North Korea's missile programme, possibly leaving in place its shorter-range missiles.
Japan also doesn't want to be left behind as negotiations proceed.