US foreign policy in 2025

As the US presidential election draws near, many are wondering what it will mean for American foreign policy. The answer is wrapped in uncertainty.

First, who will win the election? At the beginning of the summer, polls showed Donald Trump well ahead of President Joe Biden. But now that Vice President Kamala Harris has become the Democratic Party candidate, polls show her with a slight lead. The problem, of course, is that if voter sentiments can swing so quickly, predicting where they will lie on November 5 is all but impossible. While Harris has demonstrated impressive political skill, democratic politics is full of surprises. 

Second, foreign leaders and actors also have a "vote," in the sense that their behaviour can suddenly change the US agenda and the probabilities of various outcomes. The modest foreign policy that George W. Bush outlined during his 2000 campaign was nothing like the policy that he pursued after the September 11, 2001, terrorist attacks. Who knows what kind of surprise Vladimir Putin or Xi Jinping might have in store.

Campaign statements do provide some hints about policy, of course. If Harris wins, one can expect a continuation of Biden's policy, albeit with some adjustments. She seems to place less emphasis on promoting democracy – one of Biden's biggest themes – and she says a bit more about Palestinian rights. Generally, though, she would pursue the same policy of reinforcing US alliances and promoting multilateralism.

Trump is more unpredictable. While all politicians stretch the truth, he is notorious in this regard. It is difficult to know which statements might become policy. His rhetoric about unilateralism and downgrading alliances and multilateral institutions tells us something about the tenor of his foreign policy, but it does not answer questions about specific issues.

Observers often try to improve their predictions by looking at the candidates' advisers. Harris's top foreign-policy hand is Philip Gordon, a pragmatic, highly respected centrist who handled European and the Middle Eastern affairs in prior Democratic administrations before becoming the vice president's chief foreign-policy adviser.

By contrast, it is difficult to identify a comparable figure in the Trump camp – though the press sometimes mentions Robert O'Brien, Trump's last national-security adviser. What we do know is that Trump regrets having appointed traditional Republicans to key roles during his previous term, since they duly curtailed his freedom of action and made his policies more moderate than he wished.

It is also worth noting some similarities between the two candidates. Most important are their positions on China. There is now a broad bipartisan consensus that China has not played fair on trade and intellectual-property issues, and that its assertive behaviour in the East and South China Seas is threatening American allies like Japan and the Philippines. 

China has said many times that it would not rule out the use of force in seizing Taiwan, which it regards as a renegade province. In many ways, Biden continued Trump's China policy, and Harris would likely do the same, with some adjustments.

A second similarity between the candidates is their rejection of neoliberal economic policies. During Trump's presidency, the US abandoned the traditional (Reagan-era) Republican approach to trade, increased tariffs, and downgraded participation in the World Trade Organization. This was all done under the guidance of US Trade Representative Robert Lighthizer, who remains influential in Trump's circle.

Trump also spurned the Trans-Pacific Partnership that Barack Obama had negotiated, and Biden then did nothing to rejoin that agreement or to remove Trump's tariffs on imports from China. In fact, Biden went further by introducing new technology-focused export controls against China (billed as erecting a "high fence around a small yard"). With her own ties to the US tech industry as a Californian, Harris is unlikely to lower the fence. And Trump, if anything, will expand the yard.

Moreover, both Trump and Harris have pledged to increase American hard power – militarily and economically – through investments in the defence budget and the defence industrial base. Both also can be expected to continue the current nuclear-weapons modernization program, and to promote the development of new weapons that use artificial intelligence.

One of the biggest differences concerns the candidates' positions on Europe. Trump and his running mate, J.D. Vance, have made it clear that they have little interest in supporting Ukraine and NATO. Trump claims that he would end the war quickly through negotiations, and it is difficult to see how this could be done without weakening Ukraine dramatically.

In the Middle East, both candidates have pledged to maintain Israel's security and its right to self-defence, though Harris also speaks of a Palestinian right to self-determination. Both probably would urge Saudi Arabia to proceed with normalising relations with Israel, and both would take a tough line on Iran. But whereas Trump assigns low priorities to Africa and Latin America, Harris could be expected to pay more attention to those regions. 

The most dramatic difference concerns American soft power: the ability to secure desired outcomes through persuasion rather than coercion or payment. During his presidency, Trump opted for an "America First" unilateralism that led other countries to conclude that their interests were not being considered. He also openly rejected multilateralism, most dramatically by withdrawing from the Paris climate agreement and the World Health Organization. 

Biden reversed those moves, but Trump would probably reverse the reversal, whereas Harris would maintain American participation. She also would be more likely than Trump to issue statements promoting human rights and democracy.

In short, there will be large areas of continuity in US foreign policy no matter who wins the election. But the differences between the candidates' attitudes toward alliances and multilateralism are significant – and that could make all the difference. 

Joseph S. Nye, Jr., Co-Chair of the Aspen Strategy Group, is a former dean of the Harvard Kennedy School, a former US assistant secretary of defence, and the author, most recently, of A Life in the American Century (Polity Press, 2024).

Disclaimer: This article first appeared on Project Syndicate, and is published by special syndication arrangement.