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Last week in Bonn, the former capital of West Germany, the most unwelcome attendees at a U.N. summit on climate policy may have been the members of the delegation representing the Trump administration. President Trump, after all, made a great show of his opposition to the landmark Paris climate accord — one of the linchpins of his predecessor's political legacy — by announcing his country's withdrawal from the pact in June.

Trump's energy adviser, George D. Banks, promoted coal and other fossil fuels at a panel event swarmed by protesters. As he attempted to explain his boss's doubts about global warming, he trotted out lines of reasoning that one analyst deemed "zombie arguments from the 1990s and 2000s."

Meanwhile, an unofficial and dramatically different American delegation was making its presence felt. A number of prominent Democratic senators made the trip to affirm their commitment to the ongoing negotiations. Other big names, including leading business executives and California Gov. Jerry Brown, showed up and emphasized their desire to curb carbon pollution, no matter what the president says. Former New York City mayor Michael Bloomberg, a committed advocate for climate action, pitched in for a swanky pavilion that declared "We are still in!"

"We are here because it’s our responsibility to be part of the global community," said Sen. Benjamin L. Cardin (D-Md.) last week. "We’re here because it’s in our national security interests to deal with climate change." Bloomberg directly mocked the administration's climate stance: "Promoting coal at a climate summit is like promoting tobacco at a cancer summit," he joked.

The "We are still in!" pavilion in Bonn, Germany. (Lukas Schulze/Getty Images)

This kind of outreach is part of a wider trend that has emerged during the chaotic first year of Trump's rule. While the White House preaches an "America first" agenda and seeks to unravel years of global diplomacy, a coterie of governors and mayors from some of America's wealthiest and most dynamic parts of the country are moving to strengthen and build international partnerships to secure the interests of their regions and cities.

"Nearly a year into the Trump presidency, countries around the world are scrambling to adapt as the White House has struggled to fill key government positions, scaled back the State Department and upended old alliances," my colleagues Greg Jaffe and Michael Birnbaum wrote. "Now some nations are finding that even if they are frustrated by President Trump’s Washington, they can still prosper from robust relations with the California Republic and a constellation of like-minded U.S. cities, some of which are bigger than European countries."

Brown, the California governor, conducted a 10-day swing through the continent that including meetings with European officials in Brussels and an appearance in Bonn.

“The engagement against climate change must be global,” said European Parliament President Antonio Tajani during a media briefing with Brown. “In the United States there are several governors working in the right direction, even if the Trump government decided to change the line. What they are trying to do in the government of Mr. Brown is very interesting.”

The mayors of major world cities have taken a particularly conspicuous lead on climate change, given that urban centers are primary producers of greenhouse-gas emissions and often are situated along rivers and oceans, making them particularly vulnerable to rising seas. But the points of convergence between cities are hardly restricted to environmental worries.

"What may be less obvious is that when it comes to city-to-city coordination, climate change is not an outlier issue," former U.S. diplomat Ivo Daalder, the president of the Chicago Council on Global Affairs, wrote this year. "To the contrary. On inequality, immigration, health, security, governance, human rights and a host of other critical issues, cities are increasingly bypassing national governments and looking to each other for solutions."

That seems particularly necessary at a time when foreign interlocutors see the Trump administration lost in a fog of ultra-nationalism and indifferent to the principles its predecessors long upheld. They point to an understaffed State Department and a White House that seems largely uninterested in substantive engagement with other countries beyond Trump's pet issues, such as European defense spending or American trade deficits.

“There is an impression by politicians here that President Trump in person is no longer the voice of the free Western world,” Christian Ehler, a German lawmaker who heads the European Parliament’s delegation for relations with the United States, said to my colleagues. “We are much more carefully looking now to the diversity of what is being discussed in the United States, and we see that California is one of the powerhouses of the world economically."

As Jaffe and Birnbaum note, several European countries have stationed ambassadors in Silicon Valley. The Democratic mayor of Los Angeles, Eric Garcetti, recently created a new post, backed by a substantial team of Washington veterans, for a deputy mayor charged with handling the city's international relations.

"Our point is: With the disarray going on in Washington, D.C., today, you should be dealing directly with governors,” Gov. Terry McAuliffe (D-Va.) said to my colleague Dan Balz in July. McAuliffe was speaking on the sidelines of a summit of U.S. governors that hosted Canadian Prime Minister Justin Trudeau and other international leaders. “You’re not going to cut a business development deal in Washington. You need to come directly to the states,” he said.

This attitude won't make Trump happy and would probably rile the president's base, which is ever angry about Washington "globalists." The Trump presidency, which constantly seeks to weaponize resentment against "coastal elites," has deepened the rift between America's successful cosmopolitan centers and other parts of the country. And as those cities look outward for new opportunities  — even as Trump searches for ways to move against them — the divide may only get wider.

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