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The annual talk shop of world leaders at the U.N. General Assembly in New York began on Monday. Dozens of heads of government and state have descended on the city to engage in a flurry of meetings and deliver 20-minute addresses from the assembly chamber's green-marble dais. But this year’s session may be a particularly subdued affair, with numerous important statesmen, including the presidents of Russia and China, the Indian prime minister and chancellor of Germany, all skipping out.

Of course, the confab does feature a conspicuous new participant: President Trump. On the campaign trail, Trump bashed the United Nations as an entity that’s “not a friend of democracy ... not a friend to freedom ... not a friend even to the United States of America.” The organization, he said, embodied exactly the sort of tedious multilateral diplomacy and foreign interference he wants nothing to do with.

As president, Trump has somewhat ratcheted down his rhetoric. He said little on Monday about his administration’s potential move to cut U.N. funding, instead urging reform of the institution. Sitting next to U.N. Secretary General António Guterres, Trump said he wanted to see member states take bold stands “with an eye toward changing business as usual and not being beholden to ways of the past which were not working.” He even quipped to reporters that he wanted to “make the United Nations great. Not again. Make the United Nations great.”

Attention now moves to Trump’s formal speech before the General Assembly on Tuesday. But even as he and other world leaders make their addresses and chat on the sidelines, it’s difficult to see where progress will be made on the pressing geopolitical crises of the moment. Here are the big ones:

The Rohingya crisis

Burma’s top civilian leader, Nobel laureate Aung San Suu Kyi, is among the absent leaders this week. Her decision was made amid the ongoing crisis along the Burma-Bangladesh border, where a Burmese military offensive against supposed Islamist militants has led to a staggering exodus of Rohingya Muslims. A U.N. official even suggested that a campaign of “ethnic cleansing” was taking place in Burma’s Rakhine state.

Suu Kyi and the Burmese government probably will be scolded by a range of speakers at the General Assembly. On Monday, British Foreign Secretary Boris Johnson held a private meeting with Burmese officials and diplomats from Bangladesh, Indonesia, Turkey, Australia and Canada, urging humanitarian access to Rakhine and a cessation of hostilities.

“While Burma has undoubtedly made encouraging progress towards democracy in the last few years, the situation in Rakhine, the terrible human-rights abuses and violence, are a stain on the country’s reputation,” said Johnson said in a statement.

But it’s unclear whether Burma will face much more than symbolic reprimands. Suu Kyi was scheduled to deliver her first major speech on the crisis Tuesday, and there’s little indication she will show much compassion for the Rohingya. Geopolitics will stymie any push toward significant international sanctions, with both Russia and China likely to veto any Security Council resolution that would seek to punish Burma. Chinese officials have already blocked a bid by Egypt to insert language that addressed the Rohingya right to return home to Burma into a statement condemning the violence.

“This is basically an opportunity for China and a vulnerability of Aung San Suu Kyi,” Yun Sun of the Stimson Center in Washington told the New York Times. “The Chinese government says the Rohingya issue doesn’t affect us and by supporting Aung San Suu Kyi we don’t lose anything.”

The North Korean nuclear threat

At the top of the U.S. agenda is a showdown with Pyongyang. As North Korea keeps testing its arsenal and lobbing missiles over Japan, the Trump administration has engaged in a heated war of words. On Sunday, Nikki Haley, the U.S. ambassador to the United Nations, said her country had “pretty much exhausted all the things that we could do at the Security Council at this point,” referring to the rounds of tough sanctions against the North Korean regime.

“If North Korea keeps on with this reckless behavior, if the United States has to defend itself or defend its allies in any way, North Korea will be destroyed,” she declared.

Such rhetoric has come to characterize the Trump administration's approach, which partly reflects frustration with North Korea’s neighbors, China and Russia. Both of those countries are urging talks and a diplomatic resolution. Instead, Trump and his lieutenants have taken a more bellicose line.

“We used to be the strong, silent type on all of this crazy rhetoric coming out of Pyongyang, and we were the models of restrained, careful statements, and that’s not the style of this president,” retired Adm. Dennis Blair, the former U.S. director of national intelligence, said to Politico’s Susan Glasser.

But raising the pressure on North Korea could lead to dangerous fallout. “War, through miscalculation and misconception, is beginning to look probable, if not inevitable,” Gordon Chang wrote in the Daily Beast.

The possible collapse of the Iran deal

At the same time, Trump is possibly marching the world into another alarming confrontation.

The U.N. meetings bring Iranian President Hassan Rouhani to the United States, a significant visit because Tehran and Washington have no formal ties. Although Trump and his Iranian counterpart are unlikely to cross paths, let alone shake hands, plenty of sideline meetings will focus on the fate of the nuclear agreement.

Trump is desperate to end the deal, which he could start unraveling by declaring next month that Iran is not in compliance with its commitments under the agreement. (International monitors would probably disagree.) That declaration would compel Congress to decide whether it wants to slap sanctions back on Iran, and doing so could then prompt the Iranians to walk away from the deal.

Leading European officials have begged the Trump administration not take such a drastic — and, at this point, unnecessary — step.

“Exiting such an agreement would carry a high cost for the United States of America,” Rouhani said Monday in an interview with CNN, “and I do not believe Americans would be willing to pay such a high cost for something that will be useless for them.” Trump could still prove him wrong.

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