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President Trump and North Korea’s Kim Jong Un are due to meet in Vietnam next week for their second summit on denuclearization. Like the first, which took place in Singapore, there will be much pomp and circumstance: The White House is already offering fans the chance to buy a commemorative coin.

Trump has spoken warmly of his first summit with Kim. He has frequently claimed that Pyongyang has halted its overt testing of missiles and nuclear weapons, and he has offered glowing reviews of his relationship with the young North Korean leader. “We fell in love,” Trump said at a campaign rally in September. “He wrote me beautiful letters.”

But now we are into the Vietnamese new year, and that romance looks complicated. Some analysts contend circumstances have changed too much, that if the second summit is simply a repeat of the first, it will be remembered as a failure.

Last year’s meeting, while certainly historic, produced a communique that was extremely light on details. There has been little real progress made on the stated goal of denuclearization, with some moments of outright tension between Washington and Pyongyang. The second summit, scheduled Feb. 27 to 28, will need to flesh out the core of what denuclearization will look like — and chart a road map for the United States and North Korea.

Duyeon Kim, an adjunct senior fellow at the Center for a New American Security, put it this way: “The Vietnam summit this month will determine whether real denuclearization of North Korea is possible ever, and how much Washington is willing to pay for it, while ensuring the regime’s survival and the country’s prosperity.”

Trump and Kim signed an agreement that made only vague reference to nuclear weapons at the first summit in June (with the exception of a pledge to repatriate the remains of U.S. service members killed in the Korean War, which has seen some progress). But after the second summit, the devil will be in the details.

Exactly what is being offered in Vietnam will be important. Both sides will want to have something to keep momentum going. However, they will probably proceed cautiously, keeping incentives for future negotiations. U.S. officials, including Stephen Biegun, the special envoy for North Korea, have suggested that Washington views this as a step-by-step process — a contrast to Trump’s prior assessment that “there is no longer a Nuclear Threat from North Korea.”

Biegun, who was appointed after the summit last year and initially struggled to get meetings with the North Korean side, is known to have met with a number of domestic denuclearization experts in recent months. One of the groups he met with is associated with the Carnegie Endowment for International Peace, which released benchmarks for the success of the Vietnam summit.

Among the key points outlined by Carnegie’s Toby Dalton and Ariel Levite is that the two sides need to agree to a road map, while North Korea should agree to a verifiable freeze on the production of nuclear weapons along with a general increase in transparency. “As a first step to demonstrate its sincerity and commitment to making progress, North Korea should immediately cease all fissile material activity at Yongbyon and open it to monitoring,” Dalton and Levite write, referring to North Korea’s main nuclear facility.

These may be achievable goals — Kim has already offered to dismantle Yongbyon, though only after the United States makes its own concessions. But a big question is: What would Washington offer in return? One obvious suggestion is that Washington may move to pull back sanctions placed on North Korea in recent years.

“A series of more developed issues, compared to the first summit, will be discussed during the meeting,” Kim Sang-ki, director of the unification policy unit at the Korea Institute for National Unification, told the Korea Times. “They will include a lifting of economic sanctions on the North and the expansion of bilateral engagement in such areas as culture and sports.”

Other options include an “end of war” declaration to formally end the Korean War, which concluded with an armistice in 1953, or the reciprocal sending of liaison officers, a tentative step toward formal diplomatic relations, though many analysts surmise sanctions relief is a top priority for North Korea.

For U.S. negotiators, one of the biggest hurdles is reading what their North Korean counterparts are thinking. Pyongyang has been an unreliable partner in past talks, and there are plenty who fear Trump will get conned. “Basically, we’re giving Kim more time and money — money in the form of lax enforcement or nonenforcement of sanctions — to perfect the bomb,” said Sung-Yoon Lee of Tufts University in a recent interview.

Others have suggested that sometimes what the West interprets as duplicitous is actually an institutional hesitancy, perhaps caused by the pressure of living in a totalitarian state. “As a general rule, North Korean negotiators proceed cautiously, sometimes circuitously,” Robert Carlin, a former CIA and State Department analyst, wrote for the website 38 North. “The path to ‘yes’ tends not to come in a straight line.”

Trump may not be a predictable, reliable negotiator either. His timetable for denuclearization appears to have stretched dramatically as his fondness for Kim has grown. “We’re in no rush whatsoever,” Trump said this week of North Korea’s denuclearization.

That kind of rhetoric may seem like a waste of leverage, but it is also a reflection of reality: All but the most intense hawks see the window for an immediate, unilateral disarmament by North Korea as closed, if it were ever truly open. Even if North Korea agreed to denuclearization, it would almost certainly take years to complete — up to a decade, according to one plan put together by Carlin and others.

That’s one reason critics of Trump worry he could act impulsively and offer major concessions in a bid to reach a grand new deal — and with it, a domestic political win. Many hope for a road map going forward: North Korea’s nuclear weapons program may well outlast Trump’s time in office, but the president has a real chance to chart a course for eventual denuclearization.

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