American Foreign Policy in the New Trump Era

Trump’s approach to American grand strategy is clear, original and disruptive. But will it work?

On his first day as the Secretary of State, Marco Rubio told his new employees that President Trump’s foreign policy “is centered on one thing, and that is the advancement of our national interest, which they have clearly defined through his campaign as anything that makes us stronger or safer or more prosperous.” I’m sure many American diplomats in that room, if not most, did not vote for Trump. I am also sure that everyone in the room agreed with this mission statement.

Reaffirming the grand goal of U.S. foreign policy—advancing the security and prosperity of the American people—is easy. With very rare exceptions, all presidents and their administrations have put America first. What’s much harder—and more divisive—is articulating and implementing a strategy that achieves that universally recognized goal. On strategy, American presidents, diplomats, and the people have differed. Over the centuries, three big debates have shaped our foreign policy strategies: isolation versus internationalism, unilateralism versus multilateralism, and realism versus liberalism. Regarding these debates, Trump has articulated and practiced in his first term a clear preference for isolationism, unilateralism, and realism. I think he is on the wrong side in all three debates—isolationism, unilateralism, and realism are not the best approaches for making Americans “stronger or safer or more prosperous.” This makes me worried about the effective pursuit of U.S. national interests in the next four years.

Here is a quick and superficial review of the cleavages in these debates: Isolationists believe that the best way to advance American interests is to not engage with world affairs. They seek to avoid building alliances that “entangle” the United States into conflicts, prefer tariffs to free trade to isolate and protect the American economy, and dislike foreign aid and international institutions because they constrain and dilute American power, or so the argument goes. Isolationists also do not think that the world's problems are our problems. In the 1930s, isolationists argued that Italy’s invasion of Ethiopia was not our problem. Japan’s invasion of China? Not our problem. Hitler’s and Stalin’s invasion of Poland? Not our problem. Today, isolationists make the same argument about Russia’s invasion of Ukraine and a potential Chinese invasion of Taiwan.

Internationalists hold the opposite view. They believe alliances enhance American national security and share the burden of providing security; they believe in free trade and trade agreements as means for making the United States more prosperous. They think that international institutions and treaties advance American power, not constrain it. Internationalists also believe that we cannot ignore conflicts abroad—be it the invasion of Poland in 1939 or Ukraine in 2022 —because these “regional” conflicts can spill over and eventually threaten American national security directly.

Within the broader debate between militant isolationists and ardent internationalists, there are less acute divisions between advocates for entrenchment and proponents of expansionism. Entrenchment presidents like President Obama never argued for complete withdrawal from the world, just a less expansive agenda. Such presidents usually come after expansionist presidents like George W. Bush, who, after the 9/11 terrorist attacks, pivoted to a much more ambitious foreign policy agenda. (On these pendulum swings in American foreign policy, read Steve Sestanovich’s excellent book, Maximalist.)

The debate between unilateralists and multilateralists is related but distinct from the isolationist-internationalist cleavage. Unilateralists are not opposed to all American engagement with the world. But when they do engage, they want to be completely unconstrained by laws, norms, allies, or multilateral institutions. Because the world is anarchic, only the law of the jungle applies, so they argue. In the Hobbesian world, the United States will best pursue its interests by acting alone. On December 5, 2024, Elon Musk succinctly captured the spirit of this strategy when he declared, “We should not have any international treaties that restrict the freedom of Americans.”

Multilateralists hold the opposite view. They believe that American national interests are best advanced by participating in multilateral institutions and adhering to international treaties, rules, and norms. Multilateralists think that cooperation between states, for instance, through international agreements and organizations, can reduce anarchy in the world. This does not mean that multilateralists do not use force; they sometimes do, but only when authorized by the UN Security Council. For instance, Obama believed in multilateralism and therefore only intervened in Libya in 2011 after obtaining UN Security Council resolutions authorizing the use of force. President George W. Bush, on the other hand, was more of a unilateralist. After he failed to obtain the UN Security Council’s authorization to bless his invasion of Iraq, he invaded anyway.

A third big debate about strategy for pursuing American interests is between realists and liberals. I hate these labels. I see many aspects of the realist tradition as very unrealistic! And the term “liberal” implies a perspective aligned with the Democratic Party, which is not true. That said, there are clear differences between these two traditions. Like the unilateralist tradition, realists believe that anarchy exists in the world, and power and the balance of power between states are the central drivers of international politics. Regime type—that is, how the system of government is organized (e.g., democracy, dictatorship)—does not matter to them. From this analytic diagnosis of the nature of international relations comes the prescription: pursue maximalist power and do not devote any attention to worrying about trying to change the internal composition of states.

Liberals also recognize the centrality of power in shaping global affairs. But they believe that regime type matters, too. Autocracies and democracies clash and even, at times, go to war. Democracies rarely, if ever, fight each other. In American history, our greatest enemies in World War I, World War II, and the Cold War were all dictatorships. Today, our biggest adversaries—China, Russia, Iran, and North Korea—all have autocracies. The kind of economic system in place in a country also influences its international behavior. Countries with communist systems, state-dominated economies, or strong oligarchies act differently than those with free market economies. From this analytic diagnosis of the nature of international relations comes the prescription: promote democracy, capitalism, and human rights.

For many eras in American history, and especially during the Cold War and after, these three debates did not align neatly between our political parties but often were most salient within our political parties. Nixon was a realist. Reagan and George W. Bush were liberals. In the 2008 presidential election, Democratic Party presidential candidates Obama and Clinton were deeply divided over the war in Iraq. In the 1992 presidential election, Republican Party presidential candidate Pat Buchanan was an ardent isolationist, and George H.W. Bush was a strident internationalist. Every presidential administration also has had a mix of realists and liberals, unilateralists and multilateralists, and even isolationists sprinkled within internationalist administrations. Within a single leader, one can detect the proclivities of these different strategies. I worked for Obama for five years. He certainly had realist and liberal tendencies that rose and fell over time. (We discussed these two schools of thought in depth on a plane ride in August 2008.)

Trump’s Return to Office. Photo by Anna Moneymaker/Getty Images

Compared to previous presidents over the last hundred years, Trump has professed allegiance to the extreme end of all three of these debates. First, he is the most isolationist president we have had in a century. During his first term, Trump pulled out of several treaties and multilateral organizations, including the Trans-Pacific Partnership (TPP), the Paris Climate Accords, the Iran nuclear deal (JCPOA), the Intermediate-Range Nuclear Forces Treaty (INT) with Russia, the World Health Organization (WHO), and UNESCO. His tariff regime did not only target China but also our close European allies. He had minimal engagement with the United Nations and WTO, and, most shockingly, he even threatened to quit NATO. Second, when he does engage in the world, Trump’s instincts are clearly unilateral, again more so than any president that I can think of in this last century. By comparison, even George W. Bush looks like a multilateralist. Third, Trump is a hard-core realist. He has never shown any interest in advancing democracy, supporting small d democrats, or fighting autocracies. In his first term, he actually admired and embraced dictators like Putin and Kim Jong Un and disparaged many of our democratic allies. He often compared American bad actions to those of dictators. When questioned about his admiration for Putin and his violent ways, Trump shot back, “There are a lot of killers. You think our country’s so innocent?”

There is no clear evidence that Trump has changed his views on American foreign policy strategy over the last four years. In his first week in office, he already has withdrawn the United States again from the Paris Climate Accords and the WTO. He is threatening to impose more sweeping tariffs. Most strangely, as I wrote about last week here, he has resurrected a new foreign policy between imperialists and anti-imperialists that I thought we had retired a long time ago.

Compared to his first term, Trump might be more successful in implementing his radical foreign policy agenda this time. First, this time, he will not be surrounded by the “grown-ups” and the “generals” who previously constrained his most extreme impulses. Second, Trump today has a blueprint. In 2016, I think he was as surprised as I was that he won. This week, he returned to the White House with a plan for foreign policy, much of which was codified in Project 2025. That document, for instance, has a whole chapter on USAID! Third, Trump and his team now have a much better understanding of how the U.S. government works than four years ago. In Trump’s first term, the budget for democracy assistance increased substantially even though the president himself was not a supporter of advancing democracy abroad. That likely happened because Trump and his team probably did not follow these congressional appropriations very closely. That is likely to change in his second term. Finally, Trump believes he has a mandate from the American people for his foreign policy agenda. On the campaign trail, Trump never discussed his ideas about seizing Greenland, the Panama Canal, or Canada! But on his isolationist tendencies, polls show growing support.

At the same time, there will still be some constraints on implementing Trump’s foreign policy strategy.

First, his new administration is already showing signs of ideological division. Secretary Rubio and Vice President Vance have very different views on Ukraine. Trump’s new National Security Advisor, Mike Waltz, also used to be a big supporter of Ukraine. The debate about work visas for immigrants between Steve Bannon and Elon Musk was also fierce.

Second, Trump is most focused on his domestic agenda. He may not have the bandwidth to pursue revolutionary foreign policy ideas.

Third, Trump and his team have promised to purge the “deep state” of “woke” generals and “leftist” diplomats, but the reality is that thousands in the “professional state” are still on the job today. When I joined the Obama administration as a political appointee at the National Security Council on January 21, 2009, I, too, was surprised that my entire staff had worked for President Bush just the day before. However, over my five years in government, I have learned the value of these professionals; I hope the Trump 2.0 team will, too.

Fourth, we are not a monarchy. The constitution gives the president enormous power over foreign policy, but other actors get a say too—the U.S. Congress, the media, non-governmental organizations, the private sector, and Stanford professors (I’ll have more to say about that in my next essay!), and most importantly the American voters. Polls show clearly that Americans who voted for Trump cared much more about the price of eggs than any foreign policy issues. They most certainly did not sign up for invading Canada or seizing Greenland. And 73 million American voters did not support Trump. Many millions more stayed home.

Fifth, other countries—both allies and adversaries—can influence Trump's actions. They have agency, too. Trump has declared that he aims to end the war in Ukraine as soon as possible. I wish him success. But Putin has a say in whether Trump succeeds, and Zelenskyy does, too.

Finally, without any inside knowledge or data, I wonder whether Trump is truly committed to pursuing a radical foreign policy. It will take tremendous time and energy. It will divert him from his other agenda items of massive deportations, tax cuts, deregulation, and acts of revenge at home. Is he really up for that? It’s too early to tell. But stay tuned here at McFaul’s World for future updates!