President Trump shakes hands with Indian Prime Minister Narendra Modi during a meeting on the sidelines of the G-20 summit in Osaka, Japan, on Friday. (Susan Walsh/AP)

President Trump was on a mission to “save the Free World,” he declared last week, as he left for the Group of 20 summit in Osaka, Japan. But en route to Asia, the president publicly instigated a fight with India. In a tweet from Air Force One, he vowed to tell Prime Minister Narendra Modi that India’s tariffs were “unacceptable” and “must be withdrawn.”

Trump had promised Indian Americans during the 2016 campaign that the United States and India would be “best friends.” During Modi’s 2017 visit to Washington, Trump called the prime minister “a true friend.” But a $24 billion dollar annual trade deficit apparently causes friction, even among the closest friends — though India, with nearly 18 percent of the world’s population, accounts for less than 4 percent of the U.S. overall international trade deficit.

It’s India’s turn in the trade deficit hot seat

Analysts believe Trump concluded long ago that the world was taking advantage of the United States, which provided global security on the cheap and got trade deficits in return. India wasn’t a traditional U.S. ally — it didn’t want U.S. troops on bases in India and didn’t seek an explicit U.S. security commitment. And, unlike NATO allies, India hadn’t signed up to spend at least 2 percent of its GDP on defense. So Trump couldn’t complain about insufficient burden sharing.

But the president nevertheless saw India as yet another beneficiary of unwise and injurious trade practices inherited from previous administrations. India was, in Trump’s assessment, “a very high tariff nation,” one that had escaped Washington’s scrutiny.

In March 2018, the president imposed tariffs on most steel and aluminum imports, including those from India, on national security grounds. A year later, Trump ended tariff-free status for roughly $6 billion of Indian-origin goods. The latter move, while unsurprising, was especially provocative to outside observers since Trump made the announcement just one month before Modi faced national elections.

Trump’s rhetoric on India is a departure from past administrations

The Trump administration is hardly the first U.S. administration to be frustrated by Indian actions. What’s new is Trump’s appetite for brinkmanship and willingness to upset otherwise friendly relations with longtime U.S. partners, which has led to his loud complaints in public and on the record.

Beginning in the George W. Bush administration, U.S. policy toward India adopted a stated U.S. goal “to help India become a major world power in the 21st century.” This policy of strategic altruism — in which the United States sought to strengthen India without asking for anything explicit in return — saw a strong India as a crucial bulwark of stability to the east of a disordered Middle East, and as a democratic partner against growing Chinese power in Asia. The Obama administration largely maintained that policy. And despite the president’s Twitter antics, it appears to be preferred policy for large swaths of Trump administration appointees, who have prioritized managing a rising China as the centerpiece of America’s “Indo-Pacific” strategy.

Despite Trump’s rhetoric, official U.S. policy toward India retains much of its links with past administrations. The U.S. National Security Strategy and National Defense Strategy argue that U.S. advantages over great power rivals are shrinking and, as a consequence, U.S. reliance on allies and partners must increase. Here’s how this strategic vision translates, at the working levels of the U.S. government: Work more closely with U.S. partners and get them to contribute more.

By one measure, the health of the U.S.-India relationship has never been better. Washington and New Delhi continue to make agreements with lots of elaborate acronyms. The defense establishments of the two countries have operationalized a Logistics Exchange Memorandum of Agreement (LEMOA), the militaries have completed a Helicopter Operations from Ships Other Than Aircraft Carriers (HOSTAC) document, the bureaucracies have completed a Communications Compatibility and Security Agreement (COMCASA). Next up, perhaps, is an Industrial Security Annex (ISA) or a Basic Exchange and Cooperation Agreement (BECA) on geospatial intelligence.

The challenge is that the accretion of agreements may not build anything strong enough to buttress the relationship against real geopolitical travails, such as a real crisis with China, or Trump’s trade tantrums.

Trump exacerbates India’s strategic fears

Political scientists see international relationships as premised on a foundation of true shared interests, false expectations and elided disagreements. In New Delhi, Indian officials long feared that Washington would entangle India in schemes to manage the rise of China only to subsequently retrench and leave India exposed. America had the luxury of retreating behind oceans; India didn’t. On top of these worries, New Delhi doubted the reliability of a Washington that had sanctioned India repeatedly from the 1960s through the 1990s.

Thus Trump poses a great puzzle for Indian leaders. On the one hand, Trump has been tough on India’s two main adversaries — Pakistan and China — in a way no previous administration has.

On the other hand, what one analyst called Trump’s “geopolitical fickleness” exacerbates every doubt Indian officials quietly and not-so-quietly harbor. How long can the United States punish Pakistan as it seeks a quick exit in Afghanistan? Would the U.S. president really continue to favor India if China came forward with a face-saving trade deal for Trump?

While New Delhi’s ultimate solution to the Trump puzzle is unclear, the government of India appears to have concluded it needs to make a tactical move, and point out that it can pull levers against the United States. In June, India imposed retaliatory tariffs on the United States. And in a generally upbeat visit by Secretary of State Mike Pompeo to New Delhi last week, India’s new foreign minister appeared to suggest that U.S. arms sales to India — a multibillion-dollar priority for the Trump administration — could only “continue to grow” if “we display trust and confidence in each other.”

As former senior U.S. official Alyssa Ayres observes, “In the past, Washington and New Delhi have found ways to quarantine tough trade differences in order to advance relations in other dimensions.” But it remains unclear how much Trump may factor in those other dimensions — and thus whether the president’s focus on trade will shape the whole relationship.

Christopher Clary is an assistant professor of political science at the University at Albany, State University of New York. More information on his research is available at christopherorenclary.com.