Tribesmen loyal to Houthi rebels hold their weapons as they ride on the back of a truck during a gathering aimed at mobilizing more fighters into battlefronts in several Yemeni cities, in Sanaa, Yemen, Thursday, Nov. 10, 2016.

Tribesmen loyal to Houthi rebels hold their weapons as they ride on the back of a truck during a gathering aimed at mobilizing more fighters into battlefronts in several Yemeni cities, in Sanaa, Yemen, Thursday, Nov. 10, 2016. Hani Mohammed/AP

Crises from Europe to the Asia-Pacific Await Donald Trump

The world has reacted to Trump’s victory. Soon Trump will have to react to the world.

Presidential elections tend to be all-consuming in America, overshadowing everything else that’s happening in the world for months on end. But the world has a way of marching on regardless. Below are five developments in international affairs that haven’t been getting much media coverage recently, but could reach inflection points during Donald Trump’s administration. (This is a non-exhaustive list—you could easily add, say, political turmoil in Venezuela, which could present Trump with a failed state just a three-hour flight from Miami, or an escalation of Russia’s intervention in Ukraine, which would offer Trump a choice between defending Ukraine’s sovereignty and preserving good relations with Russia.)

I’ve framed the developments as questions because they are literally that. The next president of the United States has never held political office, so we can’t consult his track record in predicting how he will govern.

1) Will Iran go nuclear?

The implementation of Iran’s deal with world powers to restrict its nuclear program has been going pretty smoothly, though Iran’s tests of ballistic missiles and financial gains from the lifting of international sanctions have given American opponents of the agreement plenty to criticize. The Obama administration claims that it has prevented Iran from obtaining nuclear weapons—at the very least for the next 10 years—just as Iran was getting close to amassing enough fissile material to build a bomb. Many Republicans claim that the United States has emboldened a longtime U.S. adversary that threatens Israel and U.S. interests in the Middle East, all for an accord that won’t actually stop Iran from becoming a nuclear power in the long run.

Trump has consistently said that the Obama administration struck an awful deal with the Iranians, and that he would have negotiated a better one, but he’s been inconsistent on what he’d do as president when he inherited the agreement, which isn’t a binding treaty. At various points in the campaign, he’s said he would dismantle it, renegotiate its terms, or intensively enforce it. If the deal falls apart—for instance, through Trump gutting the pact or Congress passing new sanctions against Iran that effectively poison the accord—Iran could return to enriching uranium for potential use in nuclear weapons, at a time when North Korea’s nuclear-weapons program is steadily advancing as well.

2) Will ISIS find itself fighting a different war?

ISIS once controlled as much territory in Iraq and Syria as there is in all of Jordan, but a U.S.-led air campaign and a coalition of ground forces have stripped the group of, by one estimate, 16 percent of its territory in 2016, after losses of 14 percent in 2015. ISIS has retreated from the Iraqi cities of Ramadi and Fallujah and the Syrian-Turkish border, and may soon be forced out of its last Iraqi stronghold of Mosul. Its top strategist has been killed and its leader is likely on the run, though the organization still has support networks in other countries and the capacity to carry out terrorist attacks abroad.

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The question is whether Trump will recognize this progress as a success and follow Barack Obama’s playbook, or chuck the playbook and change the nature of the fight. Trump has characterized ISIS as so serious a threat to the existence of the United States that he’s willing to do a lot of extraordinary things to counter it—closely partner with Russia despite the tensions between the two countries, bring back the torture of terrorism suspects in violation of international law, and subject immigrants and refugees from Muslim countries to “extreme vetting” (the latest iteration of his Muslim ban). Trump has said he would “bomb the shit” out of ISIS, expressed regret that the United States didn’t “take the oil” in Iraq that helped finance ISIS activities, and explained that he wants to surprise ISIS by keeping his plan for fighting the group secret. As a result, we have no idea what bombing the shit out of ISIS really means. What’s clearer is this: If Trump teams up with Russia to fight ISIS, the Russians and their Syrian client, the Assad regime, would likely meet little U.S. resistance in wiping out the remaining Syrian rebel groups, some of which the Obama administration supported. The Syrian Civil War might end with Bashar al-Assad, or some successor, ruling over a country in tatters.

3) Will the United States shed alliances?

U.S. alliances have been in some flux during Obama’s second term. Turkey, a NATO member, has clashed with the United States over America’s support for Kurdish fighters in Syria and reluctance to extradite a Pennsylvania-based cleric who the Turkish government accuses of orchestrating a failed coup. The Philippines, America’s most important ally in Southeast Asia, has been turning away from the United States and toward China under its new president Rodrigo Duterte, who cursed out Obama for criticizing Duterte’s brutal war against drugs. Relations with Saudi Arabia have been strained ever since the U.S. signed the nuclear deal with Iran, Saudi Arabia’s archenemy. In interviews this year with The Atlantic’s Jeffrey Goldberg, Obama criticized several U.S. allies as “free riders.”

These alliances, however, could be thrown into greater flux during a Trump administration. The presidents of Turkey and the Philippines have enthusiastically welcomed Trump’s victory, perhaps because they see Trump as the polar opposite of Obama, but the honeymoon may not last. Trump could fundamentally reorient America’s alliance system by partnering with Russia to combat terrorism and prioritizing that relationship above others. And since the 1980s, Trump has repeatedly criticized U.S. military alliances with Japan, South Korea, Saudi Arabia, and European NATO members, arguing that these countries need to pay up, big-league, for U.S. protection. If these countries can’t come up with sufficient funds, and they lose America as a defender, how will they respond?

4) Will progress on climate change be reversed?

In December 2015, all the world’s nations gathered in Paris and agreed, for the first time, to cut greenhouse-gas emissions. The goal was to keep the global average rise in temperature well below 2 degrees Celsius relative to levels before the Industrial Revolution (they didn’t quite hit the target, with national pledges amounting to a reduction of 2.7 degrees Celsius). This fall, the United States and China, who together account for 40 percent of the world’s carbon emissions, ratified the accord.

Obama believes ISIS isn’t an existential threat to the United States, but that climate change is. Trump seems to believe precisely the opposite. He has suggested that climate change is a Chinese hoax and pledged to abandon the Paris Agreement. Others nations have vowed to press ahead with the pact even if the United States pulls out, but my colleague Robinson Meyer notes that Trump’s move “could shatter the international consensus on reducing greenhouse-gas emissions.” Trump’s positions on the Paris deal and on scrapping Obama’s power-plant regulations “will likely ensure that the global mean temperature rises higher than 1.5 degrees Celsius,” Meyer writes. “While that may seem like a small amount of warming, it would have devastating effects on a planetary scale, pushing weather patterns far outside what human civilization has previously experienced and ensuring mass extinctions.”

5) Will European unity fray?

One of the boldest experiments in regional integration in world history is sputtering. Britain’s recent vote to leave the European Union has encouraged anti-EU parties in other member states to campaign for their own exit referendums. And if “Brexit” actually happens, the union would lose one of its wealthiest and most powerful members, just as it struggles to recover from economic crisis. Meanwhile, many EU members are refusing to accept a quota system for resettling asylum-seekers that could help resolve Europe’s refugee crisis. An EU agreement with Turkey to prevent migrants from coming to Europe is largely working, but it’s also quite fragile. Surging populist and nationalist movements—most prominently Marine Le Pen’s National Front in France—threaten to weaken Europe from within.

Trump has referred to himself as “Mr. Brexit,” and not just because he thought he could defy the pollsters and prognosticators and pull off an upset at the polls like the Brexiteers did. (He was right!) During a visit to Scotland in the midst of the referendum, Trump said he agreed with the spirit of the “Leave” campaign. “People want to take their country back,” he explained. “They want to have independence, in a sense, and you see it ... all over Europe. You’re going to have more than just … what happened last night. ... I think it’s happening in the United States.” (Last spring, by contrast, Obama traveled to the United Kingdom to lobby against Britain leaving the EU.) Trump may well inspire and encourage additional defections from the European project. After Brexit and Mr. Brexit, what comes next?