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Last week was a whirlwind for North Korea watchers.

On Thursday, South Korean officials announced that President Trump had agreed to meet with North Korean leader Kim Jong Un by the end of May, a move my colleagues called a “high-wire gambit.” But by the next day, Trump had added conditions. White House press secretary Sarah Huckabee Sanders said Friday that Trump had agreed to meet “on the basis that we see concrete and verifiable steps.” Treasury Secretary Steven Mnuchin reiterated Sunday that Trump would meet with Kim only if there were no nuclear or missile tests.

“There shouldn't be confusion,” Mnuchin said on “Meet the Press” — perhaps wishfully.

But the lack of clarity doesn't make last week's events any less stunning. A Trump-Kim meeting could be a historic breakthrough in the increasingly tense relations between Washington and Pyongyang, and many experts expressed cautious optimism. Patrick M. Cronin, senior director of the Asia-Pacific Security program at the Center for a New American Security, praised the Trump administration's aggressive approach on North Korea.

“There is some reason to believe Kim acted at least tactically to nip the mounting pressure campaign in the bud,” he wrote for Foreign Policy. “He could read the writing on the wall: Trump meant maximum pressure until concrete results were achieved, the U.S.-South Korean alliance was holding strong despite political differences, China was increasingly on board with pressure, and elites might already be feeling the pinch from a sharp curtailment of foreign currency flowing into North Korea. Maybe now was the right time to cut a deal and at least buy more time.”

Others are more skeptical. Jeffrey Lewis, an arms-control expert at the Middlebury Institute of International Studies in Monterey, Calif., called the meeting a clear gift to Kim“White House Press Secretary Sarah Sanders has said that the United States has not made any concessions, but let’s be clear: THE MEETING IS THE CONCESSION,” he wrote, also for Foreign Policy.

He also argued that there's no evidence North Korea is willing to discuss denuclearization, which is, according to Washington, the entire point of the talks.

“Trump seems to have thought that Kim would meet to give up his nuclear weapons. But for Kim the meeting is about being treated as an equal because of his nuclear and missile programs,” Lewis wrote. “It seems that none of Trump’s aides told him the invitation was nothing special — that North Korea desperately wanted such a visit for more than 20 years. Nor did his staff consider the possibility that North Korea wasn’t offering to abandon its nuclear weapons programs. Maybe none of them realized that.”

Trump's snap decision — and the seemingly short time frame for starting negotiations — also has observers worried. “A summit should be a reward for months, even years, of careful work and actual progress. Meetings at lower levels should progress to more senior principals, and then to the heads of state,” Tom Nichols, a professor of national-security affairs at the Naval War College, wrote in USA Today. “Instead, we have yet another decision, much like the recent and incoherent announcement of tariffs, that looks like sheer impulse.”

Of course, Trump would hardly be the first U.S. president to believe that he alone can break a geopolitical deadlock.

“Trump will probably fall victim to the same conceit that most American presidents do in the sense that they [think they] personally, in their interactions with foreign leaders, can work their magic, away from the plodding diplomat,” a top Republican foreign-policy official wrote to Axios. “There is such a desperate desire for a magic solution to this otherwise insoluble problem that people lose touch with reality.”

In reality, the success of the meeting could hinge less on Trump and more on making progress on core issues of trust that are extremely difficult to solve. “For North Korea to lay down its nuclear weapons, Kim must be genuinely convinced that the United States will not harm his regime,” Patricia Kim, the Stanton Nuclear Security Fellow at the Council on Foreign Relations, wrote for The Washington Post. “This won’t be easy, given Washington’s track record of taking out dictators, most recently in Iraq and Libya.” North Korea will be no less pressed to prove its own credibility.

There are additional concerns, Kim writes: questions about the rules of engagement — what actions would cause talks to collapse? — and whether the two sides can ever share the same end goal. The United States may demand that North Korea give up its nuclear weapons, but history offers almost no examples of success.

In the history of nuclear weapons there has been only one country that voluntarily gave up its weapons and the program that produced them, and that is South Africa,” physicist Jeremy Bernstein wrote in the New York Times. “That should tell us something about how hard it will be to persuade North Korea to dismantle its large and very sophisticated weapons program.” North Korea, which already boasts of advances in nuclear weapons and missile technology, will probably be especially hard to convince.

Even so, a meeting between the two men offers an opportunity to tamp down tensions, if nothing else. As Isaac Stone Fish argues in the Atlantic, it's “probably the least bad way to reduce Pyongyang’s desire to harm the United States.” The sit-down might well convince Kim that the United States does not pose an existential threat and even increase trust between the two nations. That, he says, is worth giving Kim the recognition he craves.

But if Trump isn't careful, says Victor D. Cha, the president's former pick for U.S. ambassador to South Korea, the meeting could fail — and send relations down an even more dangerous path. “Failed negotiations at the summit level leave all parties with no other recourse for diplomacy,” Cha wrote in the New York Times. “In which case, as Mr. Trump has said, we really will have 'run out of road' on North Korea.”

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