One of U.S. President Donald Trump’s few consistent views is that the United States must replace grand, multilateral bargains with more favorable bilateral deals. As he said of the Trans-Pacific Partnership in a 2016 speech, “We need bilateral trade deals. We do not need to enter into another massive international agreement that ties us up and binds us down.” But two years into Trump’s presidency, the results are underwhelming. A deal with China has proved elusive. Trump’s new agreement with Canada and Mexico amounts to little more than a rebranded NAFTA. A grand bargain with North Korea still seems unlikely, notwithstanding the announcement on Friday of a second summit between Trump and North Korean leader Kim Jong Un. U.S. alliances with Japan and South Korea are fraying, and relations with Russia, Saudi Arabia, and Turkey are little better than they were two years ago, despite Trump’s efforts to cultivate personal relationships with those countries’ leaders. The art of the deal has fallen flat.

It’s not hard to see why. Trump’s bull-in-a-China-shop performances at international summits—by now so familiar that December’s relatively uneventful G-20 came as a surprise—and his fixation on particular issues, such as allies’ defense spending, trade deficits, and European car imports, at the expense of the bigger policy picture, drive home that Trump is better at dismantling deals than making new ones.

But there’s an even more basic problem with his diplomacy: Trump does not put in the legwork. He travels abroad little, and the trips he does make rarely end up achieving what he wants.

HOMEBODY

Presidential time is a scarce resource. Where a president travels sends an important signal about his priorities, because foreign visits invest U.S. prestige in the relationship with the host country and stake the president’s reputation on the outcome of the meeting. Trump’s predecessors planned their travel carefully, and they did a lot of it.

Trump does not. His hopes for striking new bilateral deals rest on his ability to build relationships, but he has made few foreign trips for one-on-one sessions with host country leaders. Excluding visits to countries hosting routine international gatherings (such as the G-20) and third-party summits (such as the one between Trump and Russian President Vladimir Putin in Finland and the Singapore summit with Kim), Trump has made only 11 visits for such one-on-one sessions. (One was a quasi-multilateral visit to France for World War I commemorations last November, which we count as bilateral since Trump met separately with French President Emmanuel Macron.) That figure compares to 19 such trips for Barack Obama during his first two years in office, 13 for George W. Bush, and 16 for Bill Clinton.

Of course, leaders also meet bilaterally on the sidelines of multilateral gatherings, although such meetings are not the main focus of their trip. At first glance, including such meetings, Trump’s total number of bilateral trips (18 visits to 17 countries) approximates those of his three immediate predecessors in their first two years—19 visits to 19 countries for Clinton, 19 visits to 16 countries for Bush, and 21 visits to 20 countries for Obama.

But adding these sideline meetings exaggerates Trump’s facetime with host country leaders. Although sideline meetings can be useful, the multilateral setting means they are usually shorter and less concentrated on bilateral relations than true bilateral visits. These totals also obscure a dramatic drop-off in purely bilateral visits with host country leaders in Trump’s second year in office. Trump made only two such visits in all of 2018—the return visit to France, which had a multilateral component, and a much-delayed trip to the United Kingdom, which itself came only as a stopover between a NATO summit and the meeting in Finland with Putin. Bush, by contrast, made most of his bilateral trips in his second year—the year following the September 11 attacks—travelling to Asia and Latin America as well as to U.S. allies in Europe and North America.

By any reasonable count, therefore, Trump travels far less than his predecessors did for the purpose of holding bilateral meetings with a host country leader. Although he talks about foreign policy as a transactional affair, Trump is barely a deal-seeker, much less a dealmaker.

MOST PRESIDENTIAL TRAVEL IS BORING

Although he clearly dislikes travel, Trump’s dogged pursuit of splashy, televised meetings with North Korea’s leader shows that he nonetheless values diplomacy that makes news. Trump is not alone in equating diplomacy with grand occasions. The public tends to picture presidents travelling to look the enemy in the eye, as in the great Cold War summits, or to break new diplomatic ground, as when Richard Nixon restored U.S. relations with China in 1972.

The problem is that such occasions are rare. Most diplomacy is boring—indeed, the routine is usually the point. Our research shows that during the Cold War and in the decades since, U.S. presidents and their secretaries of state traveled disproportionately to major U.S. trading partners and recipients of U.S. arms and military assistance. Powerful countries were also more likely to receive a visit than weaker ones. Official travel largely involves presidents and secretaries of state regularly doing ordinary things in predictable places.

Trump disdains the mundane. But he misses that in diplomacy, uninteresting does not mean unimportant. Research by political scientists shows that face-to-face diplomacy helps leaders assess each other’s intentions, send and read signals, and foster trust. Presidential visits to regular destinations, such as international summits, matter because they rely on earlier legwork by diplomats to produce deals and statements the leaders can sign. The secretary of state, backed by the ambassador and experts in the host country, can provide the experience, knowledge, and attention to detail the president cannot. Trump’s Singapore summit failed because U.S. diplomats had little chance to make it worthwhile.

The routine nature of most diplomacy means that the absence of a visit can send a powerful message. Trump has failed to visit either Germany or Mexico for a one-on-one summit, major omissions for a U.S. President. (Trump did travel to Hamburg for the G-20 summit in July 2017, and met Chancellor Angela Merkel individually to resolve disagreements that could disrupt the summit.) Bush and Obama both traveled to Mexico in their first two years in office. And Clinton, Bush, and Obama all visited Germany for one-on-one meetings in the same period.

Just as bad as not making a trip is scheduling one, and then cancelling it. In November, Trump scratched a planned visit to Colombia, a close U.S. ally. That the trip would have been easy—a stopover on the way back from the G-20 Summit in Buenos Aires—added insult to injury. Trump had met Colombian president Iván Duque on the sidelines of the UN General Assembly in September 2018, praising Duque’s “strong stance on drugs” and his efforts to take in refugees in the region, including from Venezuela. Trump has emphasized threats from Latin America, so the twice-canceled visit was a missed opportunity to reward the most Trump-friendly regime in the region. Sometimes, the demands of the office make cancelling a trip unavoidable; Obama canceled a trip to Asia in 2013 amid a government shutdown, leading some allies to question his administration’s commitment to the region. But Trump’s already-limited travel gives those countries he spurns less reason to suppose that he means to reschedule.

ACCEPT NO SUBSTITUTES

Although Trump has stuck close to home, his subordinates have followed more normal diplomatic itineraries. Rex Tillerson, Trump’s first secretary of state, generally copied his predecessors in his travel choices. Mike Pompeo, his successor, has done the same. By the end of 2018, Tillerson and Pompeo had traveled to a total of 53 countries. On almost 90 percent of those visits, they met one-on-one with leaders of the host country. The countries they chose—NATO members, U.S. trading partners, and major regional powers—included roughly three-quarters of those visited for such bilateral sessions by at least one secretary of state in the first two years of the Clinton, Bush, and Obama administrations. In total, through 2018, Trump’s two secretaries of state had made 101 country visits, about the same as the average figure—107 visits—for the prior three administrations.

Tillerson and Pompeo have not been alone in picking up the slack. Vice President Mike Pence, former Secretary of Defense James Mattis, and even Trump’s family members have traveled in Trump’s absence. Pence has crisscrossed the globe to visit 29 countries, roughly 80 percent of them for the one-on-one meetings with host country leaders that Trump has spurned. Mattis traveled more frequently than his immediate predecessors did, matching the intensity of his counterparts at the State Department.

Trump’s surrogates may be more welcome presences given Trump’s habit of haranguing even close U.S. allies in person. But surrogates and even family members are no substitute for the real thing when there is little prospect of a presidential visit to seal any deal—and when any progress can be undone from afar by a presidential tweet. A surrogate visit can also make the president’s absence more glaring, as when Melania Trump visited Africa last October without her husband.

UNWELCOME GUEST

Over the next two years, Trump may be tempted to look for diplomatic triumphs abroad as a respite from deadlock at home. Presidents often turn to foreign policy when their domestic agendas stall. Indeed, Trump has already started to make this turn. His Christmas night trip to Iraq last December—his first visit to American troops in a combat zone—came after a week of domestic turmoil. But as so often with Trump’s visits, things did not go smoothly. Iraqi Prime Minister Adil Abdul-Mahdi was unable (or unwilling) to travel to meet Trump at a moment’s notice, and Iraqi politicians accused Trump of violating Iraq’s sovereignty by failing to announce his trip beforehand.

Even if Trump were to get past his allergy to visiting foreign capitals, he might find himself an unwelcome guest.Foreign leaders have discovered that Trump is often a disruptive—and lonely—presence. In June 2018, Trump blasted the just-agreed G-7 communique—and the Canadian Prime Minister—as Air Force One took off from Ottawa. During Trump’s July 2018 visit to the United Kingdom, British Prime Minister Theresa May hosted a dinner at Blenheim Palace for Trump—only to have a tabloid interview in which he blasted her handling of Brexit published while they ate. Trump’sdecision to be driven to the World War I commemoration in Paris last November, rather than walking in the rain with fellow dignitaries, revealed a United States that has rejected the inconveniences of cooperation to reap the alleged benefits of going it alone.

In the weeks after Trump won the presidency and took office, world leaders lined up to visit him at Mar-a-Lago. Two years in, NATO leaders have downgraded the alliance’s planned 70th anniversary summit in Washington to a foreign ministers’ meeting. The world seems to have decided that it wants to see less of Trump, not more. Absent accomplishments—or an agenda—that could motivate additional trips, and short now of enthusiastic hosts, Trump’s travel schedule seems unlikely to grow in 2019 and 2020.

Trump might still find it useful to collect some frequent flier miles. The problem is that to strike the bilateral deals he wants, he will have to learn the central lesson of high-level diplomacy: it’s the visit—and what you do while you're there—that counts, not the souvenir.