Scarcely 12 weeks into his presidency,
The president remains an unpredictable and impulsive leader on the world stage, diplomats say — one called him a "nuclear whirling dervish" — and he could swiftly pivot back to some of the unconventional proposals he offered in the 2016 campaign.
And while other politicians might be pummeled for so many high-profile flip-flops, Trump seemingly has inoculated himself so far by boasting that his "flexibility" as an outsider makes him a good negotiator.
Thus far, at least, Trump has yet to "tear up" the landmark Iran nuclear disarmament deal, as he had once promised, or to reverse President Obama's historic opening to Cuba, as he vowed.
He has not moved the U.S. Embassy in Israel from Tel Aviv to the disputed city of Jerusalem, as he had promised, after Arab allies warned of the turmoil it would cause.
He affirmed the "one China" policy that is critical to Beijing after initially questioning it, and said this week he would not declare China a currency manipulator, as he had often pledged.
The North Atlantic Treaty Organization is "no longer obsolete," he said at a news conference Wednesday with the secretary-general of the 28-nation military alliance, a direct U-turn from his stated position shortly before he took office.
His decision to launch cruise missiles into Syria in response to a poison gas attack put him squarely in the internationalist camp that Presidents Clinton and
Bush, in a rare public comment about the current occupant of the White House, told NPR on Thursday that the "realities of the job" often reverse a candidate's isolationist views.
To be sure, not everything is reverting to traditional policy.
The administration has not withdrawn from the historic Paris accord on climate change, which sets targets for emissions that cause global warming, as Trump had suggested he might.
But he has signed executive orders to void Obama-era limits for coal-burning plants and other environmental regulations intended to help the United States, one of the world's biggest emitters of greenhouse gases, meet its targets.
He has squabbled with the leaders of Mexico and Australia, two of America’s closest allies, and held awkward meetings with German Chancellor
And human rights and democratic reform, pillars of U.S. foreign policy since the Cold War, moved to a back burner as Trump has lavished praise on Egyptian President Abdel Fattah Sisi and other autocrats.
Trump's lauding last year for Russian President Vladimir Putin has come to naught, just as Obama's early efforts to reset relations with Moscow went nowhere.
Relations "may be at an all-time low," Trump acknowledged Wednesday after the White House accused Moscow of trying to cover up Syria's role in the April 4 poison gas attack, and Russia accused the Trump administration of committing a war crime by attacking Syria.
The White House insists Trump is not abandoning his convictions but rather is adapting to new circumstances. His critics argue that Trump never really had convictions and that he merely takes the position of the latest cable news show he saw — or the last person to whom he spoke.
After Trump told visiting Chinese President
"After listening for 10 minutes, I realized it's not so easy," Trump told the Wall Street Journal this week. "I felt pretty strongly that they had a tremendous power" over North Korea. "But it's not what you would think."
White House Press Secretary
"The president's tough talk on a variety of issues was to get results for the American people," Spicer said.
Richard Haass, president of the Council on Foreign Relations and a former senior State Department official, said Trump's foreign policy shifts have been welcomed abroad and in the U.S. foreign policy establishment.
But "discomfort and uncertainty" continue to unnerve leaders and diplomats because it is unclear whether Trump's shifts are permanent, he said.
"And the mere fact that a candidate and then a president could embrace such radical ideas will leave a residue," Haass added.
James Jay Carafano, a fellow at the conservative Heritage Foundation and key advisor to the Trump team, said it was a mistake to take most of Trump's campaign promises seriously, at least on foreign policy.
"There are no U-turns here, no 180-degree" flip-flops, he said. "There was never an actual plan to go soft on Russia or to pull away from NATO."
Those notions, he said, were campaign rhetoric aimed at motivating his base or ginning up news coverage. In extensive meetings with Trump's staff, he said, policy was much more measured, deliberate and mainstream.
Carafano pointed to Japanese Prime Minister Shinzo Abe, the first foreign leader to meet with Trump at the president's Mar-a-Lago club in Florida, as the "poster child" for how to deal with the administration: Ignore everything Trump has said and walk into the meetings with a fresh slate.
Some of Trump's shifts may owe to internal realignments within the White House.
Trump's decision to fire Michael Flynn as national security advisor, and replace him with H.R. McMaster, a respected figure in national security circles, seems to be pushing policy closer to the mainstream.
McMaster, in turn, has brought in respected officials like Fiona Hill, a highly regarded hard-liner on Russia.
And if Trump's chief strategist, self-professed nationalist Stephen K. Bannon, is fading in influence, as has been widely reported, that too could create more room for mainstream opinion.
But those looking from outside remain nervous.
"Will these shifts endure?" said Haass. "Or does this indicate that populism, nationalism and 'America first-ism' are now running in the American political bloodstream?"