Believe me.” U.S. President Donald Trump has used that phrase countless times, whether he is talking about counterterrorism (“I know more about ISIS than the generals do. Believe me”), building a wall along the U.S.-Mexican border (“Believe me, one way or the other, we’re going to get that wall”), or the Iran nuclear deal (“Believe me. Oh, believe me. . . . It’s a bad deal”).

Trump wants to be taken at his word. But public opinion polls consistently indicate that between two-thirds and three-quarters of Americans do not find him trustworthy. The global picture is no better. Most citizens of traditional U.S. allies, such as Australia, France, Germany, Japan, Jordan, Mexico, South Korea, and the United Kingdom, say that they have no confidence in the U.S. president.

In other words, Trump suffers from a credibility gap. This is, perhaps, unsurprising. According to The New York Times, Trump said something untrue every day for the first 40 days of his presidency. His actions speak even louder. Trump has sown doubt about some of the United States’ oldest and most important commitments, such as its support for NATO—an alliance Trump described as “obsolete” in January, before declaring it “no longer obsolete” in April. He has flip-flopped on policy positions, publicly undermined the efforts of members of his own administration, and backpedaled on diplomatic agreements, including the Paris climate accord and the Iran nuclear deal.

The United States does not derive its credibility from the words of the executive alone, but Trump’s behavior carries consequences. As the president undermines the nation’s credibility at home and abroad, allies will hesitate to trust American promises, and U.S. threats will lose some of their force. The risks of deadly miscalculation will increase. And to demonstrate its resolve, the United States may need to take more costly and extreme actions. Other sources of credibility, such as American military prowess and a general faith in U.S. institutions, may mitigate some of the damage wreaked by Trump. But there is no substitute for a president whose words still matter. 


The Nobel laureate and nuclear strategist Thomas Schelling once wrote that “face is one of the few things worth fighting over.” For much of the twentieth century, policymakers believed that their own credibility was essential to making threats believable and to reassuring allies and adversaries alike that they could trust U.S. commitments. In the 1950s, for example, the United States entered the Korean War in part to demonstrate its resolve to actively counter the Soviet Union. A similar concern about reputation kept U.S. troops in Vietnam long after policymakers had concluded that the United States was losing the war. In the post–Cold War era, most American leaders have considered credibility essential to the task of maintaining the U.S. alliance system and the postwar liberal order. Such thinking played a role in U.S. interventions in Haiti, Kosovo, and Iraq. The rationale for these interventions varied, as did their outcomes, but in each case, leaders backed their words with action. 

In international politics, an actor’s credibility is tied to its reputation, a characteristic that political scientists generally split into two varieties. What Robert Jervis calls “signaling reputation” refers to an actor’s record of carrying out threats or fulfilling promises. “General reputation,” on the other hand, refers to a broader range of attributes, such as whether an actor is cooperative or sincere. These two forms of reputation can affect each other: for example, sustained damage to a state’s signaling reputation may erode its general reputation for trustworthiness. However, a country’s general reputation can also be distinct. Before the Korean War, for example, the United States had made no specific commitment to South Korea. Choosing to intervene, therefore, did not affect the United States’ signaling reputation but may have contributed to a general reputation for resolve.

In international politics, an actor’s credibility is tied to its reputation.

Context can also affect credibility. For example, a president may not be perceived as trustworthy when he makes assurances to allies but may still be considered credible when he threatens military action. Or he may be seen as trustworthy on social or economic issues but not on foreign policy. Sometimes, a president’s credibility at home can affect his credibility abroad. In 1981, U.S. President Ronald Reagan followed through on his threat to fire more than 11,000 air traffic controllers after they had violated federal law by going on strike. A number of policymakers and observers—including George Shultz, who became U.S. secretary of state the following year, and Tip O’Neill, then Speaker of the House—reported that this move had significant, if unintentional, consequences for U.S. foreign policy: the Soviets learned that Reagan didn’t bluff. 

Some scholars are skeptical that reputations matter. The political scientist Daryl Press argues that credibility has nothing to do with a leader’s record of following through on threats. Instead, adversaries evaluate the balance of military capabilities and the interests at stake. Press argues that during the Cuban missile crisis, for example, members of the Kennedy administration viewed Soviet Premier Nikita Khrushchev’s threats as highly credible, even though Khrushchev had repeatedly backed down on his ultimatum that Western forces withdraw from West Berlin. In Press’ view, Khrushchev’s credibility stemmed not from his signaling reputation but from Washington’s view of the nuclear balance of power and Soviet interests. Similarly, the political scientist Jonathan Mercer argues that, historically, backing down from a threat has not led countries to develop a reputation for weakness among adversaries, and standing firm has not led to a reputation for resolve among allies.

The empirical evidence these scholars have gathered is important. But their view by no means represents the scholarly consensus. According to the political scientists Frank Harvey and John Mitton, for example, a reputation for following through on threats significantly increases a state’s coercive power. Focusing on U.S. interventions in Bosnia, Kosovo, and Iraq, they show that adversaries studied what the United States had said and how it had behaved in comparable situations to infer its resolve and to predict its likely actions. My work with the political scientist Alex Weisiger has shown that countries that have backpedaled in past crises are much more likely to be challenged again, whereas countries with good reputations for resolve are much less likely to face military confrontations. Other studies have documented how states that break their alliance commitments develop a reputation for being unreliable and are less likely to earn trust in the future. A good reputation, this body of work demonstrates, remains crucial for successful diplomacy. 

Trump at a NATO summit, May 2017
Jonathan Ernst / Reuters


Unfortunately, the reputation of the U.S. presidency has eroded in recent years. Trump deserves much of the blame—but not all of it. The United States’ signaling reputation began to decline in the summer of 2013, after Syrian President Bashar al-Assad breached U.S. President Barack Obama’s “redline” on chemical weapons. In August 2012, Obama had stated that the mobilization or use of these weapons would “change [his] calculus” on Syria, a remark that many interpreted as a threat of military action. In August 2013, Assad launched a series of sarin gas attacks against rebel strongholds, killing 1,400 Syrians. Yet instead of responding with military strikes, Obama agreed to a Russian-brokered deal in which Assad pledged to dismantle his arsenal of chemical weapons. 

In an interview with The Atlantic’s Jeffrey Goldberg, Obama defended his decision by saying that “dropping bombs on someone to prove that you’re willing to drop bombs on someone is just about the worst reason to use force.” But this was a straw man. Few analysts were suggesting that Obama should pursue a bad policy solely on reputational grounds; however, there are political and strategic costs when the president makes a promise and then fails to act. If Obama had not intended to follow through on his threat, he should not have issued it in the first place. And ultimately, the diplomatic solution did not work: Assad has continued to use chemical weapons.

Regardless of whether they supported or opposed Obama’s decision not to intervene more forcefully in Syria, Republicans and many Democrats believed that the redline episode had damaged the country’s credibility. Hawks argued that to restore the United States’ reputation for resolve, Washington should be more willing to use military force. But this was a misleading, and potentially dangerous, assessment of what needed fixing in U.S. foreign policy after Obama’s departure. Credibility requires consistency, not belligerency. The next president could have repaired the damage by demonstrating the integrity of American assurances and threats.

Instead, Trump has complicated the situation by showcasing both toughness, which may have some strategic advantages, and impulsivity, which undermines his credibility. By bombing Syria, reengaging in Afghanistan, and applying more pressure on North Korea, Trump may have gained a general reputation for resolve and conveyed that he is more comfortable using military force than his predecessor. Yet the president’s track record of flip-flopping on key campaign pledges, his bizarre and inaccurate outbursts on Twitter, his exaggerated threats, and his off-the-cuff assurances have all led observers to seriously doubt his words. 

Trump and Theresa May in Brussels, May 2017
Trump and Theresa May in Brussels, May 2017
Christian Hartmann / Reuters

The list of Trump’s inconsistencies is long. After winning the 2016 race but before taking office, Trump spoke by phone with Tsai Ing-wen, the president of Taiwan. This represented a major breach of protocol; in order to avoid angering China, no U.S. president or president-elect had spoken to the leader of Taiwan since 1979, when the United States broke off diplomatic relations with the island. After the call, Trump declared that he was considering abandoning the “one China” policy, the foundation of the U.S.-Chinese relationship for the past four decades. But in February 2017, he reconsidered and decided to uphold the policy after all. During the campaign, Trump threatened to launch a trade war with China and pledged to label Beijing a currency manipulator. He also implied that the United States should abandon its commitment to nuclear nonproliferation, suggesting that Japan and South Korea should develop their own nuclear weapons. He has subsequently backtracked on all these positions.

The ongoing crisis with North Korea is the latest manifestation of the same pattern. At the beginning of his presidency, Trump described the North Korean leader Kim Jong Un as a “smart cookie” and said that he would be “honored to meet him.” He has subsequently taken to referring to Kim as “Little Rocket Man,” and in September, he threatened to “totally destroy” North Korea.

In other instances, Trump may have upheld his own signaling reputation at the country’s expense. For example, Trump followed through on a campaign promise when he decided not to certify the Iran nuclear deal in October. Because he demonstrated consistency, this decision may have bolstered his personal signaling reputation. But by reneging on a formal U.S. commitment without presenting evidence that Iran was not abiding by the treaty, Trump also imperiled the general reputation of the United States. Such a move could undermine Washington’s diplomatic clout in future negotiations. If other countries believe that American political commitments cannot survive a transition of power, they will be less likely to make significant or painful concessions. Trump’s earlier decision to withdraw from the Paris climate agreement presented a similar problem. Of course, any American president who wishes to change the status quo must wrestle with the dilemma of how to keep his own promises without jeopardizing the credibility of his country. But it is unclear that Trump has any concern for the larger reputational consequences of his decisions. 


Some in Trump’s circle claim that there is a brilliant strategy underpinning his erratic behavior and that the president understands the ramifications of his unsteady public posture. According to this view, Trump’s seemingly irrational statements are part of a calculated strategy to make adversaries think that he is crazy. In September, for example, Trump told his trade representative to intimidate South Korean negotiators. “You tell them if they don’t give the concessions now, this crazy guy will pull out of the deal,” Trump said, according to Axios, referring to the U.S.–South Korean free-trade agreement. When it comes to North Korea, the logic is simple: if Trump can convince Kim that he is irrational, and therefore willing to accept the steep costs of a military confrontation, then he might scare the North Korean leader into capitulation.

Trump would not be the first U.S. president to attempt this strategy, which scholars call “the madman theory,” or “the rationality of irrationality.” During the Vietnam War, President Richard Nixon reportedly asked his national security adviser, Henry Kissinger, to tell the Russians and the North Vietnamese that he was unpredictable and might even use nuclear weapons in Vietnam. But they saw through Nixon’s bluff, and the gambit failed. The first rule of playing the madman game is to never publicly state that you are playing the madman game. Trump has done just that. Pursuing this approach will only make him appear unsophisticated and immature. 

Another explanation that Trump’s defenders have offered is that the president purposefully creates ambiguity in order to keep adversaries off balance. During the campaign, Trump said that he would not “broadcast to the enemy exactly what my plan is.” It’s certainly true that when carefully crafted and consistently implemented, ambiguous statements can offer strategic benefits, such as allowing leaders to speak to multiple audiences, who may have opposing interests, without alienating any of them. But Trump’s statements are not strategically ambiguous; in fact, they are generally quite clear. The problem is that they are inconsistent. The impulsive tone and the fact that some of his statements are communicated via Twitter in the middle of the night further reduce their credibility. 

When asked to account for Trump’s behavior, some of his supporters have even suggested that the president’s words should not be taken literally. The Trump adviser Kellyanne Conway told CNN’s Chris Cuomo that the president should be judged based on “what’s in his heart” rather than “what’s come out of his mouth.” U.S. allies, faced with the daunting task of discerning what lies in Trump’s heart, are unlikely to find this advice reassuring.


It is possible that the American public and the rest of the world have already gotten used to Trump’s unpredictable statements and contradictory tweets. In some cases, his reputation for not living up to his word may even be reassuring: the world knows that he is unlikely to follow through on some of his more disturbing pronouncements, such as his threat to “totally destroy” North Korea. But this is small comfort. What happens when his word really needs to count? How can the United States deter adversaries and reassure allies in the next crisis when the president cannot be trusted to credibly communicate U.S. intentions?

Optimists argue that Trump will eventually learn the importance of keeping his word. In this view, Trump’s inconsistency results from his lack of experience, especially when it comes to foreign policy. On occasion, Trump himself has admitted this. Trump criticized China for failing to restrain North Korea but then reversed himself after speaking about it with Chinese President Xi Jinping. “After listening for 10 minutes, I realized it’s not so easy,” Trump told The Wall Street Journal. Similarly, the president changed his stated positions on the U.S. war in Afghanistan, Russia’s meddling in the 2016 election, and U.S. policy in Syria after he was elected, presumably because he had learned more about those issues. 

It is not unusual for a president’s views on foreign policy to evolve in office. But what is disturbing about Trump’s process of learning is that his new views remain as fluid as his old ones, and they do not appear to emerge from thoughtful reevaluation and reflection. Instead, they appear to be determined by his mood, or by the views of the last person he has spoken to or watched on cable news networks. 

Tillerson and Mattis at a press conference in Washington, June 2017
Tillerson and Mattis at a press conference in Washington, June 2017
Kevin Lamarque / Reuters

Other possible sources of comfort are Trump’s advisers, whom many observers have taken to referring to as “the grownups” in the administration. White House Chief of Staff John Kelly, Secretary of Defense James Mattis, National Security Adviser H. R. McMaster, Vice President Mike Pence, and Secretary of State Rex Tillerson have all sought to add coherence and stability to U.S. policy by clarifying the president’s statements—or by seeming to ignore them altogether. These people are now the face of American public diplomacy: observers turn to them to understand U.S. policy. This would be reassuring if the president were playing along. But Trump has undermined his advisers’ efforts to salvage Washington’s reputation by publicly undercutting them. Just one day after Tillerson confirmed that the United States was speaking directly with the North Koreans, Trump tweeted that his secretary of state was “wasting his time.” “Save your energy Rex,” he wrote. Such statements—even if they are intended to push Kim to make concessions—are likely to sow confusion in Pyongyang. Trump’s rhetoric on North Korea has undermined the United States’ signaling reputation and could potentially lead to a disastrous and avoidable war. 

If there is any ground for cautious optimism, it is that the president’s reputation is not the only factor adversaries and allies consider in order to discern U.S. intent. As skeptics of the importance of reputation might point out, U.S. military power, widespread knowledge of the United States’ vital interests, and a long record of taking military action to defend the status quo in various parts of the world continue to allow the United States to dissuade adversaries from crossing well-established redlines. The credibility of a country does not depend solely on the credibility of its president. Foreign observers may not trust Trump, but they may still retain some degree of confidence in American political institutions and public opinion as constraints on the president’s actions. 

At the same time, however, the president’s compromised signaling reputation increases the likelihood that adversaries will misperceive American redlines and misjudge U.S. reactions, especially in contentious regions such as eastern Europe and the Middle East. World leaders may also feel that it is now acceptable to dismiss or ignore the president of the United States when it is convenient for them to do so; they could be forgiven for coming to this conclusion when they read that Tillerson referred to Trump as a “moron.” (Tillerson’s spokesperson has denied this—but Tillerson himself has not.) 

Trump has undermined his advisers’ efforts to salvage Washington’s reputation by publicly undercutting them.

A damaged reputation may also make it harder for the United States to achieve its objectives through coercive diplomacy—the threats and promises that have traditionally worked because they were understood to put U.S. credibility at stake. Under Trump, the United States may have to resort to more risky tactics to demonstrate resolve, such as military brinkmanship or even military force. Such tactics carry serious risks of unnecessary escalation.

With the president’s signaling reputation diminished, the United States will also have to work harder to convince its allies that it will stand by its commitments. Washington’s partners are likely to demand more concrete demonstrations that U.S. security guarantees remain intact. Reduced trust in American protection may lead U.S. allies to become more self-reliant (as Trump wants them to be), but it could also embolden U.S. adversaries to more aggressively test boundaries. It would not be surprising, for example, if Russian President Vladimir Putin decided to probe the extent of U.S. support for Ukraine.


The long-term ramifications of Trump’s credibility crisis remain unclear. The United States cannot control the conclusions that others draw from the president’s behavior. But international observers will look at how the U.S. political system responds to Trump’s statements, and when and how it counteracts them. Even if American foreign policy during the Trump administration remains consistent and coherent in action, if not in rhetoric, the United States has already paid a significant price for Trump’s behavior: the president is no longer considered the ultimate voice on foreign policy. Foreign leaders are turning elsewhere to gauge American intentions. With the U.S. domestic system so polarized and its governing party so fragmented, communicating intent has become more difficult than ever. The more bipartisan and univocal U.S. signaling is, the less likely it is that Trump’s damage to American credibility will outlast his tenure. 

For now, however, with Trump’s reputation compromised, the price tag on U.S. deterrence, coercion, and reassurance has risen, along with the probability of miscalculation and inadvertent escalation. Trump may think that a predictable and credible foreign policy is a sign of weakness. He is wrong. For a small revisionist power such as North Korea, appearing unpredictable may allow a leader to temporarily punch above his weight. But whether Trump likes it or not, the United States is a global superpower for whom predictability and credibility are assets, not liabilities. 

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  • KEREN YARHI-MILO is Assistant Professor of Politics and International Affairs at Princeton University and the author of the forthcoming book Who Fights for Reputation? The Psychology of Leaders in International Conflict.
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