IR Experts See Glaring Differences Between Harris and Trump

As usual, foreign policy has not taken center stage in the 2024 U.S. presidential election campaign—even though the results of past elections have often had a major impact on Washington’s approach to the world. According to international-relations (IR) experts, this year will be no different: The outcome of the Nov. 5 election will have big implications for U.S. foreign policy.

In mid-October, the Teaching, Research, and International Policy Project at William & Mary’s Global Research Institute, with support from the Carnegie Corporation of New York, surveyed IR scholars at U.S. colleges and universities about the consequences of the presidential election for U.S. foreign policy. The results we report below are based on responses from the 705 scholars who participated. (Complete survey results can be found here.)

By significant margins, the experts we surveyed expect stark differences between the policies that either Vice President Kamala Harris or former President Donald Trump will pursue if elected president.

Just as important, they expect that different outcomes will result from those respective policies. The two candidates diverge sharply on the climate crisis, U.S. membership in NATO, nuclear cooperation with Iran, trade, and foreign assistance. But the IR scholars say that the election results will have less of an effect when it comes to U.S. use of force and conflict escalation in the Middle East, Ukraine, and Taiwan.

Regardless of the candidates’ policies, the IR experts see a large gap between Harris and Trump in their abilities to manage foreign policy, command U.S. forces, and implement their agendas on the global stage. Simply put, the experts say, Trump doesn’t make the grade.

How do the candidates differ?

IR experts see glaring contrasts between Harris and Trump when it comes to U.S. foreign policy. By large margins, respondents report differences in U.S. participation in international institutions across a range of issues.

When asked to estimate the probability that the United States would withdraw from the Paris Agreement under a Trump or a Harris administration, IR scholars on average said that there was an 80 percent chance that Trump would withdraw but only a 4 percent chance that Harris would. Similarly, the experts give a 38 percent chance that the United States would withdraw from NATO under Trump but only a scant 1 percent chance of that happening under Harris.

On nuclear cooperation, IR scholars think that there is a 35 percent chance that the United States will sign a new nuclear agreement with Iran if Harris is elected but only a 7 percent chance if Trump is elected. The predicted differences between the candidates extend to trade, where respondents on average see a whopping 80 percent chance that the United States will raise tariffs under Trump but only a 30 percent chance of that under Harris.

U.S. foreign assistance will also be quite different depending on the outcome of the election, according to the experts. They estimate that the prospect that U.S. foreign aid—a term IR experts use generally to refer to economic development assistance—will increase under Harris is 56 percent but only 20 percent under Trump.

Military assistance levels will likely differ, as well. As vice president, Harris has been clear about her view that Israel has a right to defend itself, but she has also been critical of its military operations in Gaza. Not surprisingly, IR experts see a considerable difference between the candidates on the question of increasing military aid to Israel; they give a 75 percent chance that Trump will increase U.S. military assistance to Israel if elected and a 54 percent chance of the same thing happening under Harris.

That prediction is flipped for Ukraine. IR scholars say that there is a 63 percent chance that Harris will increase U.S. military aid to the country amid its war with Russia, compared to only a 16 percent chance with Trump.

Is there a bipartisan foreign policy?

At first glance, IR experts predict smaller but substantial differences between the two presidential candidates on the use of military force, with Trump expected to be more restrained than Harris. When asked which candidate “would use military force abroad more often,” 26 percent of respondents selected Harris, compared to Trump’s 14 percent.

However, the largest percentage of respondents (44 percent) said that the outcome of the election wouldn’t affect how often the United States deploys military force abroad.

The experts’ views on this issue appear to have changed in the last four years. In our survey ahead of the 2020 presidential election, 46 percent of experts said that the outcome of the vote didn’t matter for use of force questions. At the same time, nearly identical proportions of respondents thought that Joe Biden (16 percent) and Trump (17 percent) would commit U.S. forces internationally.

IR scholars see other similarities between the candidates on foreign policy. When asked to estimate the probability that China would use force against Taiwan under a Trump or a Harris administration, the experts said there was a 32 percent chance under Trump and a 25 percent chance under Harris. Experts also predict that defense spending will increase regardless of who wins: a 76 percent probability in a new Trump administration, compared to a 67 percent likelihood in a Harris administration.

Given their contrasting predictions about U.S. military aid under Trump versus Harris, it is perhaps surprising that the experts see little difference in the probability of the conflicts in the Middle East and Ukraine widening based on who wins the White House. On average, respondents put the probability of Russia using nuclear weapons in Ukraine at 13 percent under Harris and 17 percent under Trump.

Similarly, IR scholars predict the chances that “more states will become involved in direct military conflict in the Middle East” at 41 percent under Harris and 50 percent under Trump.

Who will be the most effective foreign-policy leader?

Regardless of specific issues, Harris outperforms Trump when it comes to expert predictions about effectiveness and competence in the foreign-policy arena. When asked, “Which of the following presidential candidates do you think would most effectively manage foreign-policy issues facing the United States today?” a resounding 92 percent of the IR experts chose Harris, while only 8 percent selected Trump.

These findings parallel those from 2020, when 95 percent of the experts surveyed said that Biden would manage foreign policy most effectively, while only 5 percent thought that Trump would.

There are few self-described Republicans in our sample—just 4 percent of respondents, compared to the 67 percent of self-described Democrats and 25 percent of independents. Still, nearly one-third (29 percent) of the Republican experts report that they believe Harris would most effectively manage foreign policy. Only 1 percent of Democrats say the same of Trump. (For more information on our sample, see the survey report.)

The experts also overwhelmingly express greater faith in Harris as head of the U.S. military. On the question of how confident they were in each candidate’s ability to be an effective commander in chief, the gap between the two candidates was striking. Eighty-seven percent of experts said they were either “very confident” or “somewhat confident” in Harris’s ability, but only 6 percent said the same of Trump.

These results parallel those from our May 2020 survey, in which we asked IR experts whether Biden or Trump would exercise good judgment as commander in chief. At the time, just 5 percent respondents strongly or somewhat agreed that Trump would exercise good judgment in the role, compared to Biden’s 88 percent.

A sizable minority of self-identified Republicans within our sample share their Democratic colleagues’ concerns about Trump’s abilities as commander in chief: Forty-two percent of the Republicans say they are “not too confident” or “not confident at all” of Trump’s abilities to command U.S. forces, compared to only 4 percent of Democrats who say the same about Harris.

Similarly, 29 percent of Republican experts say they are very or somewhat confident of Harris’s abilities as commander in chief, but only 1 percent of the Democratic experts expressed confidence in Trump.

Unlike the experts, the U.S. public sees little difference between the two candidates on this question. In a Sept. 1-3 survey by the Economist and YouGov, 45 percent of respondents said that they were very or somewhat confident in Trump’s ability to be an effective commander in chief, and 43 percent said the same of Harris.

Another possible measure of the foreign-policy effectiveness of a president is the way foreign leaders respond to their rhetoric, actions, and policies. When asked, “In your opinion, which of the following statements best describes how the outcome of the 2024 presidential election might shape the willingness of foreign governments to cooperate with the United States?” a decisive 84 percent of the IR experts said that foreign governments would be more willing to cooperate with a Harris administration.

Twelve percent of respondents said that foreign governments would be as likely to cooperate with either candidate, but just 2 percent said they would be more willing to cooperate with a second Trump administration.

We also asked IR scholars how effective each candidate would be in achieving their foreign-policy goals in a single term, regardless of their stance on their respective agendas—a measure of managerial competence. On average, respondents gave Harris a 52 percent probability of achieving her foreign-policy goals, while they gave Trump only a 32 percent chance.

As a group, IR scholars are not known for their tendency to agree. Nevertheless, of the experts we surveyed, 90 percent report that they would vote for Harris if the election were held today. Only 4 percent said that they would vote for Trump.

Among the experts, Republicans expressed a willingness to cross party lines in this election; thirty percent of Republican scholars surveyed report that they would vote for Harris over Trump. In a striking contrast, less than 1 percent of the self-described Democrats said they would vote for Trump.

Although the experts believe some foreign-policy outcomes, such as conflict escalation or defense spending, might not differ greatly under a Harris or Trump administration, they predict significant gaps between the presidential candidates on issues including U.S. participation in international institutions and military assistance.

The overwhelming consensus among these IR scholars is that Harris would be more effective at managing international challenges. The experts clearly believe that the choice voters make on Nov. 5 will have lasting implications for the direction of U.S. foreign policy and its global impact.