The result is a foreign policy approach marked by Trump's tough rhetoric and break with conventions that his supporters are hailing as a refreshing change and his detractors warn could have dire consequences for the United States and its allies.
"The United States no longer makes empty threats," Trump said. "When I make promises, I keep them."
While the outcomes remain uncertain on Iran, North Korea and the embassy move, the President and a new circle of close national security advisers argue they are already disproving the old arguments for caution and consistency.
"Events have transpired in a way that has given the president heightened confidence in his instinct on all three of these topics," said one US official familiar with discussions on each subject.
Trump is firm in his view that tough posturing and a disregard for diplomatic norms are effective tools of US power that past presidents were too timid to employ, current and former officials said.
The foreign policy priorities of Trump's predecessor, former President Barack Obama, are often the stick by which Trump measures his own performance.
"The lesson that America learned, painfully, a long time ago, but that Dean Acheson once said, is we only negotiate from positions of strength," national security adviser John Bolton said after Trump announced his exit from the Iran deal. "It was a lesson that the last Administration did not follow."
Acheson, who as secretary of state from 1949 to 1953 was an original Cold Warrior, held that the US should defer negotiation with the Soviet Union until it could be confident that its positions were stronger than Moscow's.
Bolton said the Iran decision would "establish positions of strength for the United States."
"It will have implications not simply for Iran, but for the forthcoming meeting with Kim Jong Un of North Korea," Bolton said. "It sends a very clear signal that the US will not accept inadequate deals."
"Inadequate" is mild by comparison to Trump's critiques of the 2015 international nuclear pact as "the worst deal ever made" and "insane."
Close allies and many of his original team of top national security advisers told Trump that leaving the deal would be dangerous or counterproductive.
His action killed the hopes of European allies that they might string the US decision out for months and perhaps broker a new agreement with Trump that could satisfy some of his complaints.
Antony Blinken, a former senior foreign policy adviser for Obama and former vice-president Joe Biden, said the Trump team sees the Iran deal in simplistic terms. The wholesale US exit may set up downstream problems, including in Syria, where Iran is a major player, and probably in North Korea, where Kim may draw the lesson that the United States can't be trusted, Blinken said.
"It's detailed. It's more complicated than they think," Blinken said in an interview. "Maybe he'll defy all laws of geopolitical gravity, but I doubt it."
US allies also were aghast at Trump's sudden announcement in December that the US would immediately recognise Jerusalem as Israel's capital and move its embassy there. Trump had promised as a presidential candidate that he would make the move, but he had initially deferred to aides and allies who argued it was risky.
Trump chafed at following other presidents who have continually deferred the embassy move since the 1990s and told friends and political audiences that he would be the president who finally had the courage of his convictions.
"Very proud of it," Trump said earlier this month of his decision.
Trump's daughter, Ivanka Trump, and son-in-law and adviser Jared Kushner are among those planning to attend the opening of the new US Embassy in Jerusalem on May 14. The symbolic move upends long-standing US policy that the US would not prejudge the disputed status of Jerusalem by unilaterally declaring it as the Israeli capital.
Under guardrails of peacemaking that Trump rejects as outmoded, Jerusalem was an issue to be left for resolution between Israel and the Palestinians. The US Embassy's location an hour away in Tel Aviv was a sign that Washington would not put a finger on that scale.
Trump has pointed to the Jerusalem embassy issue as a particular example of what US officials and others described as the "Chicken Little" effect - when dire warnings against something Trump wants to do seem like hollow threats after the fact.
"He heard from many people - commentators, observers and Cabinet members - that there would be all kinds of negative repercussions if he were to make that decision," to move the embassy, said the US official. "Violence, the endangering of US forces all over the Islamic world, all kinds of warnings, virtually none of which have proven to be the case, at least thus far."
Palestinian Authority President Mahmoud Abbas has refused to meet with top US officials since the embassy decision was announced in December, forcing the White House to shelve efforts to restart peace negotiations. But the Trump Administration rebuffed that criticism, as well as the milder complaints from allies such as Britain and France, and moved on.
"There were similar 'the sky is falling' warnings last summer and [autumn]," when Trump signalled that he would eventually back out of the Iran nuclear deal, "and of course there were warnings about the belligerent language with North Korea last year and how that would lead us to war," the US official said. "That has proven not to be the case."
Trump takes credit for reversing a decades-long narrative of failure in North Korean diplomacy with his stunning decision to meet face to face with Kim.
"We are really doing well with North Korea," Trump said during a rollicking, campaign-style address last week to the National Rifle Association.
"Look, for years, for years, they've had this problem and everybody has said, sort of, 'Oh, don't talk! Don't talk! Please don't talk!' " Trump said to laughter. "The last Administration had a policy of silence," he continued, mimicking a horrified tone. 'Don't talk! You may make them and him angry! Don't talk!'"
Trump said the same dynamic applies to his view of the Iran deal. He mocked former Secretary of State John Kerry, as a poor negotiator, and said the Obama Administration was foolish.
"But we have great things going on with respect to North Korea," he said. "You know what gets you nuclear war? Weakness gets you nuclear war, being weak."
