The speech offered the most fleshed-out definition yet of the Trump doctrine, a style of big-power nationalism that the president and his advisors have also labeled "principled realism" and "America first." It brushed aside decades of American policy in favor of an approach that was dominant in the 1940s and 1950s.
"The nation-state remains the best vehicle for elevating the human condition," Trump declared. "Our success," he said, "depends on a coalition of strong and independent nations that embrace their sovereignty, to promote security, prosperity and peace for themselves and for the world."
The speech's emphasis on nationalism was consistent with Trump's campaign themes, but its assertive view of the U.S. role in the world broke sharply with some campaign rhetoric that suggested a more isolationist path.
It contrasted even more directly with the foreign policy approaches of his two most recent predecessors.
Gone was President Obama's focus on climate change and human rights, as well as his concern with the limitations of U.S. military force and emphasis on international organizations.
Instead, the speech featured a denunciation of Obama's nuclear accord with Iran and a repeated emphasis on the need for the U.S. to consider its own citizens before those of other nations.
"You really are seeing 'America first' campaign rhetoric being turned into a global strategy," said Frederick Kempe, president and chief executive officer of the Atlantic Council, a Washington-based think tank.
But the speech also drew a sharp contrast with the foreign policy approach of the last Republican president, George W. Bush, who justified his administration's invasion of Iraq in part by emphasizing the hope that removing dictatorial regimes in the Middle East would lead to the spread of democracy.
"The defense of freedom requires the advance of freedom," Bush declared in one of his main foreign policy speeches.
Trump, by contrast, downplayed the idea that the U.S. should intervene to spread democratic systems worldwide.
"We do not expect diverse countries to share the same cultures, traditions or even systems of government," Trump said. "But we do expect all nations to uphold these two core sovereign duties: to respect the interests of their own people and the rights of every other sovereign nation."
As the speech showed, Trump accepts that rival powers like China and Russia will pursue their own goals, which will often run afoul of American values or even global norms. He treats relationships with those countries as transactional, aimed at serving security or economic goals. He thanked both Moscow and Beijing for help with sanctions against North Korea and avoided any criticism of either by name, making only oblique references to instability in Ukraine and the South China Sea.
Yet even as Trump preached a live-and-let-live philosophy with America's most powerful rivals, he made exceptions for weaker ones. He made clear that his respect for sovereignty does not cover the behavior of smaller countries that he considers to be "rogue regimes," employing his most bellicose rhetoric to threaten them with destruction and belittle their leaders. He directly and at length denounced North Korea, Iran and Venezuela and offered shorter criticism of Cuba.
Despite the audience of global leaders, the criticism of Venezuela and Cuba, in particular, were among several nods Trump made to his domestic political base. He branded North Korean leader
Trump's address left some in his audience filled with misgivings.
"This was the wrong speech, at the wrong time, to the wrong audience," Swedish Foreign Minister Margot Wallstrom told the BBC.
Europeans who sit in Trump’s nationalistic camp, however, were gleeful. Nigel Farage, an enthusiastic proponent of “Brexit,” the vote last year for Britain to depart the
Trump's speech rejected Bush's argument that the best path to security involves promoting U.S.-style democratic systems around the world.
Bush's clearest expression of his foreign policy doctrine came in a speech at the National Defense University at Ft. McNair, a few miles from the White House, on March 8, 2005, where he offered a strong defense of U.S. intervention overseas.
"Our strategy to keep the peace in the longer term is to help change the conditions that give rise to extremism and terror, especially in the broader Middle East," Bush said, adding that the region had "been caught for generations in a cycle of tyranny and despair and radicalism."
Bush railed against "decades of excusing and accommodating tyranny, in the pursuit of stability," but Trump, who has lavished praise on strongmen for their ability to contain extremists in their countries, said that economic prosperity would be the chief force leading to stability.
But like so much else in the Trump presidency, a bigger feature of his foreign policy is a direct assault on Obama.
The former president, along with some
"This administration takes exactly the opposite approach to that and probably the exact opposite approach to the people in that room," said James Carafano, a fellow at the conservative Heritage Foundation who advised Trump during the transition. "Institutions are not what holds the world together. They are standing on what holds the world together."
Obama, in his foreign policy speeches, emphasized the importance of international institutions and the limitations on the United States' ability to use its military to enforce its will.
"Since World War II, some of our most costly mistakes came not from our restraint, but from our willingness to rush into military adventures — without thinking through the consequences, without building international support and legitimacy for our action or leveling with the American people about the sacrifice required," he said in his speech to the graduating class at West Point in 2014.
Obama said the U.S. should use the military "when our core interests demand it," but warned against going it alone.
"We cannot exempt ourselves from the rules that apply to everyone else," he said. "I believe in American exceptionalism with every fiber of my being. But what makes us exceptional is not our ability to flout international norms and the rule of law; it's our willingness to affirm them through our actions."
Trump, by contrast, spoke of an America that would not only act primarily in its own interest, but would also encourage others to do the same.
"As president of the United States, I will always put America first," he said. "Just like you, as the leaders of your countries, will always and should always put your countries first."
That remark drew scattered applause in an audience split between internationalists and leaders of countries who have sought for decades to avoid U.S. scrutiny of their domestic and foreign behavior.
Staff writer Laura King contributed to this article.