Trump's year of shattered norms leaves world on edge
President Donald Trump erupted onto the global stage under the isolationist banner "America First" - bent on tearing the multilateral world order down to its foundations.
Now, at the end of his first year in office, the United States and its shell-shocked allies face several escalating crises that could plunge the world into devastating new conflicts.
When Trump came to office in January, his predecessor Barack Obama warned that North Korea's breakneck dash to develop long-range nuclear missiles was his most pressing threat.
As 2017 comes to an end, that threat has soared dramatically - last month Kim Jong-Un test fired an ICBM and boasted that his nuclear arsenal can now hit any city on the US mainland.
Trump himself has stirred tensions with reckless language, sneeringly branding Kim "Little Rocket Man" and threatening to visit "fire and fury" on his authoritarian regime.
Alongside the bravado, US diplomats have put together a punishing international sanctions regime designed to force Pyongyang to the table - so far to no avail.
South Korea and Japan - also in North Korea's firing line - are facing a potentially cataclysmic conflict and China is concerned about chaos erupting on its border.
But, perhaps for the first time it is not the erratic behaviour of the North Korea dictator that worries the world, but the unpredictable signals coming from the White House.
"I think before President Trump there was always a consistency about US policy and preferences, with some exceptions," said Paul Stares, senior fellow at the Council on Foreign Relations.
"But President Trump's behavior, the erratic decision making, the tweeting and seemingly impulsive behavior has I think rattled a lot of capitals around the world," he said.
Bluster and brinkmanship
To produce the annual Global Conflicts to Watch survey, which rated US wars with North Korea or Iran as "tier one" threats, the CFR interviewed 436 government officials and outside experts.
Stares, the author of the report, told AFP he found wide concern.
"It's just difficult to determine whether this is bluster and brinksmanship or a real determination to use force," he said, citing fears of conflict with North Korea, Iran and even Russia.
"Looking ahead to 2018, I don't think anybody is really confident that another year will go by without a serious crisis."
Trump has blown hot and cold on the North Korea sanctions strategy, at one point warning Secretary of State Rex Tillerson he was "wasting his time" in pursuing diplomatic contacts.
But the threat of US preemptive military action has remained a constant, even if many experts and - privately - serving officials admit it looks like far too risky a prospect.
With North Korean artillery poised just a few miles outside the South Korean capital and Pyongyang warning the US base on Guam could be "enveloped in fire," military action looks dicey.
But the diplomatic track is a narrow one and Kim has shown no particular enthusiasm for it himself, insisting he plans on becoming the world's greatest military nuclear power.
Trump's brinkmanship here doesn't seem to be helping, and now tensions with Iran threaten to start a new front in the many wars still roiling the broader Middle East.
The new president's contempt for the nuclear deal signed by Iran, Obama's administration and the great powers Britain, China, France, Germany and Russia has stoked tensions.
When Trump ruled that the Iran deal was no longer in US interests, CFR president Richard Haass tweeted: "Trump foreign policy has found its theme: 'The Withdrawal Doctrine.'"
As Barbara Slavin, of the Atlantic Council, told AFP at the time: "Trump... fails to understand that the US is most powerful when it leads and shapes an international consensus."
Along with Trump's decision to pull out of the Paris climate change accords, the Iran deal row has best symbolized Trump's "America First" break with multilateral diplomacy.
Since his first weeks in office, Trump has also railed against America's traditional allies, accusing them of short-changing America by failing to find mutual defense pacts.
If Trump had made good on his plan to forge warmer ties with Vladimir Putin's Russia, then his more prickly and distant relations with Europe might have caused less anxiety.
But the already ugly relationship between Obama's Washington and Moscow has, if anything, worsened since US intelligence accused Russia of interfering in the US presidential race.
Meanwhile, Trump has shown far more respect for strongmen like China's Xi Jinping, Egypt's Abdel Fattah al-Sisi or Turkey's Recep Tayyip Erdogan than he has for traditional US allies.
A less stable world
He has hit out at Britain's Prime Minister Theresa May and Germany's Chancellor Angela Merkel on Twitter, accusing them of being lax in the battle against Islamist extremism.
And, having ditched the TPP trade pact that was meant to bind small east Asian neighbors under US influence to contain China, he is now threatening the NAFTA deal with Canada and Mexico.
Last week, German Foreign Minister Sigmar Gabriel warned that Trump's abdication of US leadership "is accelerating a change in the world order" and that Europe should look to itself.
And that was before Trump broke with decades of US peacemaking practice and unilaterally recognised the divided and disputed city of Jerusalem as Israel's capital.
Arab leaders were predictably appalled at what they saw as a reckless snub to the Palestinian cause, but the chorus of condemnation was international and near universal.
Celia Belin, visiting fellow at the Brookings Institution, sees a theme running through Trump's most isolationist stances: they are gestures to please US electors and donors.
Indeed, in a speech on Monday to launch his first National Security Strategy, Trump declared: "America is coming back, and America is coming back strong" -- a message clearly aimed at his base.
On climate, Iran and Jerusalem he has signed off on a vow given to part of his electoral base, without really committing Washington long-term to anything new, Belin said..
Nevertheless, she told AFP, the very fact that US allies and foes feel forced to react to Trump's domestic posturing poses risks: "The problem often comes from external overreaction."