(CNN)Donald Trump is turning the world upside down.
Some US enemies like Russia are becoming his friends, and longtime US allies like Germany are wondering whether America will be there for them any more.
Geopolitical groups and alliances like the EU and NATO that have underpinned US global leadership for generations are reeling from Trump's disparaging comments.
Amid the tumult, world leaders are hurriedly repositioning themselves to deal with the new world disorder that the incoming American president seems to herald.
China, for example, despite its Communist political system is moving into a vacuum left by Trump's hostility to free trade deals to position itself as the champion of unfettered and open commerce.
Russian President Vladimir Putin is emerging as Trump's most vocal defender, despite allegations of Moscow having cyber hacked in the US election.
In the Arab world, US allies are mustering to head off the firestorm they fear if Trump honors his campaign vow to move the US Embassy in Israel from Tel Aviv to Jerusalem.
And in the Western Hemisphere, another traditional American friend, Mexico, is insisting it won't pay for the wall Trump has pledged to build on the Southern border. Even Canada is bracing for tense ties with its neighbor since the President-elect has promised to renegotiate NAFTA.
It all means that the 45th president will take office with foreign allies and adversaries alike puzzled -- and, in some cases, alarmed -- that the certainties which have underpinned US foreign policy for generations no longer seem to apply.
America, always looked to for stability, continuity and as a guarantor of the liberal world order, now could become under Trump one of the most disruptive global forces -- at least if he follows through on his threats.
His hyperactive transition that has rattled the rest of the world will ensure he faces a string of simmering foreign policy questions as soon as he takes office.
US presidents have for decades based policy toward China on the need to avoid a clash between the world's last real superpower and the dominant power in Asia. Trump, however, seems to be doing exactly the opposite.
He's spent his transition tweaking Beijing over the status of Taiwan, warning against its territorial ventures in the South China Sea, and warning of a tough new initiative to wring a better deal on trade issues out of the Asian giant.
Many foreign policy experts agree that Washington needs to adopt a more robust posture toward China and accuse the Obama administration of not doing enough to protect US interests in the region.
But few would endorse Trump's chosen strategy of sending volleys toward Beijing on Twitter.
China's President Xi Jinping on Tuesday, in unusually frank terms for a Chinese leader, delivered a speech at the World Economic Forum in Davos that appeared to be an open repudiation of much of Trump's emerging China policy.
He denied that Beijing was guilty of devaluing its currency as charged by the President-elect and warned that a trade war would benefit no one.
"There's no point in blaming economic globalization for the world's problems," Xi told the world's economic elite at the Swiss ski resort.
Xi also warned that the world must remain committed to free trade and said protectionism was akin to locking "oneself in a dark room," apparently taking aim at Trump's threats to impose tariffs on Chinese goods because of his belief Beijing has ripped off America in their economic relationship.
Xi also delivered a veiled warning to Trump not to tear up the global pact to limit greenhouse gas emissions last year, following the President-elect's warnings to do just that once he comes into office.
Xi suggested that China intends to move quickly to identify economic opportunities from what it clearly believes is a pullback by the new Trump administration on leadership on global trade.
US-Russia relations haven't been this bad since the end of the Cold War.
The Obama administration and the Kremlin have been estranged over President Vladimir Putin's apparent attempts to undermine US power and Western-style liberalism, over the incursion into Ukraine and an alleged Russian espionage operation to help throw last year's election to Trump.
Now Putin, who is hoping Trump's vow to improve relations will mean he is open to Moscow's foreign policy priorities, is paying Trump back for his warm comments toward the Russian leader throughout his campaign and transition.
"I don't know what he will be doing on the international stage. So I have no foundation to criticize him nor to defend him," Putin said on Tuesday.
The Russian leader dismissed accusations that Moscow's intelligence agencies had amassed incriminating financial and personal information against Trump in order to compromise the new US president.
"These things that have been alleged are clearly false information," Putin said.
But the solicitous comments that fly back and forth frequently between Trump and Moscow are causing consternation among foreign policy experts and sparking alarm about the President-elect's motives in Europe.
Some are noting that Moscow has far more to gain than the US through a possible rapprochement, including its hopes for a lifting of US sanctions, de-facto recognition of its annexation of Crimea, and a more skeptical US view of NATO.
Comments by Trump in an interview with the Times of London and the German newspaper Bild over the weekend questioning the utility of the Western alliance, predicting more departures from the EU, and recreating some kind of great power deal-making relationship on issues like fighting terrorism and bargaining nuclear weapons, caused alarm throughout Europe.
"What Mr. Trump articulated in this series of interviews ... that is exactly the goals and aspirations of the Kremlin: to erode NATO 's credibility, to erode the European Union and to conquer and divide, to get to a great power relationship on arms control where it is back to the future and two great powers will solve everything," said Heather Conley, director of the European affairs program at the Center for Strategic and International Studies.
"Those are Russian interests," she added.
It takes a lot to shock German Chancellor Angela Merkel. And, publicly at least, she was unruffled when Trump implied to the European journalists that he trusted Putin just as much as he did , at least for now.
But the idea that an American President could be as warm to a Russian leader accused of interfering in the US election than a German chancellor shocked many observers.
"Chancellor Merkel is the leader of Germany, which has been a very close American ally for decades," former US Ambassador to Ukraine Stephen Pifer told CNN on Tuesday.
"To put them on the same plane is a pretty remarkable statement that has caused a lot of concern not just in Washington, but I think among American allies in Europe about what the Trump presidency is going to mean for how the United States engages with Europe and deals with Russia."
NATO and the European Union
Trump's statements in the weekend interview triggered disbelief in Europe.
NATO and the European Union are considered centerpieces of a largely successful political effort to purge Europe of the bloodletting that stained its history for hundreds of years.
Yet Trump seems to have little use for either institution, which are both already facing pressure from the populist economic forces that the President-elect harnessed in the US election as well as Moscow's most belligerent behavior since the end of the Cold War.
Trump was asked whether a strong Europe or stronger nation-states was most important to the US.
"Personally, I don't think it matters much for the United States. I never thought it mattered," he said. "Look, the EU was formed, partially, to beat the United States on trade, OK? So, I don't really care whether it's separate or together, to me it doesn't matter."
Trump's comments represented a departure from decades of US foreign policy. Despite tensions and differences with the bloc, Washington's preference has always been for a strong, united EU because it represents a fellow anchor of the world's liberal, open, trading and political system.
Trump's attitude toward NATO caused similar disquiet among Atlanticists.
The 28-nation Western alliance was set up in the late 1940s to guard against a rising Soviet threat. Many of its members, particularly in former Warsaw Pact countries now feel a similar threat from Moscow's territorial maneuverings.
The President-elect, however, considers NATO "obsolete" largely because he believes it is not doing enough to deal with terrorism, despite the fact that the only time that NATO's Article 5 mutual defense provision has ever been invoked was after a terrorist attack — on September 11, 2001.
Since then, thousands of NATO troops have served in Afghanistan, fighting to stop the war-ravaged country from again becoming a haven for extremist groups like al Qaeda.
"We were attacked on 9/11, and not any of these countries and they sent their young men and women to serve in Afghanistan, and over 1,000 were killed in Afghanistan," Arizona Republican Sen. John McCain said on CNN's "New Day" on Tuesday. "Not because they were attacked but because we were attacked."
Former Sen. and Middle East peace negotiator George Mitchell, meanwhile, argued that Trump risked subverting one of America's great achievements: the building of a new transatlantic order from the rubble of two world wars in which 68 million people died.
"I believe historians will judge that to be one of America's finest hours," said Mitchell on CNN Tuesday.