The Paris Agreement on climate change works by a delicate bit of magic.

The treaty aims to reduce the world’s greenhouse-gas emissions, but it legally requires no one to actually stop emitting greenhouse gases. Instead, it advances a set of loose and voluntary norms for getting to the final goal. In 2015, every country announced a (nonbinding) plan in which they promised to (eventually) slow down pumping carbon dioxide and methane into the atmosphere. In 2018, and every five years afterward, all the countries will get together again and announce new promises.

This looseness was intentional. The accord’s architects hoped to nudge everyone into bringing down their emissions together—but they didn’t (and couldn’t) force any one nation to do it. More pointedly, they also could not compel a Republican-controlled U.S. Senate to ratify any binding international climate treaty. So Paris trades in signals, not sacrifice; unanimous resolutions, not top-down restrictions. John Kerry said during negotiations that it sends “literally a critical message to the global marketplace.” In truth, this is pretty much the only thing it does.

The Paris deal worked as long as Barack Obama was president, and it would probably have worked under a President Hillary Clinton, too. Some senior U.S. official would attend the meeting every year to clamor about the document’s importance, and investors would get the message and plunge more money into renewable-energy infrastructure and research.

President Trump, however, has speculated about leaving the treaty since its completion. If he stays in the treaty, he will do so only begrudgingly. That’s why some climate leaders are now wondering: Will the Paris agreement be stronger without the United States—at least as long as its president doubts climate change?

Luke Kemp, a political scientist at Australian National University who has attended many climate negotiations, gets to the point in pithy piece at The Conversation: “Money and emissions are all that matter.” (He made the same argument in a paper in Nature Climate Change last week.)

Neither money nor emissions will change if the United States is actually a member of the Paris treaty, he says. The accords don’t require the U.S. to commit money to the Green Climate Fund, a UN pool meant to help developing countries prepare for the consequences of global warming. Under Trump, it won’t.

More importantly, the agreement also won’t change how much heat-trapping gas escapes from American smoke stacks, tail pipes, or farm land. Trump has already begun to weaken many of the domestic programs—such as Obama’s Clean Power Plan for the electricity sector, and the greenhouse-gas CAFE standards for cars—that would have added teeth to America’s Paris goals. (Kemp argues that, without them, the country will “probably miss its climate target.”)

Kemp also worries about the cascading effects of having an indolent United States in treaty meetings. If America misses its global target—and nothing happens—will the momentum that sustains Paris halter and fall apart? There remain many governing details of the treaty that have yet to be finalized, too. Negotiators will spend time between now and 2020 committing them to paper. If the U.S. stays in, Rex Tillerson’s State Department will retain a veto power in these talks. Will it weaken the treaty?

Joseph Curtin, one of Ireland’s leading climate-policy wonks and a member of its official climate advisory council, also believes the United States should exit the treaty. Paris, he argues, is a “club for countries who are part of a global effort to tackle dangerous climate change.” The U.S. doesn’t make that cut anymore.

As part of his pitch, he turns one of the most familiar arguments for staying in Paris on its head: that oil and coal companies like Exxon, Shell, and Peabody Energy support U.S. involvement in the treaty. (Peabody, the largest U.S. coal company, has long lobbied against any kind of climate policy, so its support for Paris is a surprise.)

If all these fossil-fuel companies care about global warming, he asks, where were they when the Trump administration was weakening every meaningful domestic climate policy?

“The current debate is really between those who want to leave Paris and totally deny climate change, and those who see Paris as a branding and lobbying opportunity,” he says. Therefore, the U.S. should leave, so the American public can understand the true stakes of the fight:

Polling suggests that the vast majority of Americans favor staying in. Should the U.S. leave, however, the moral outrage of these constituents could be a powerful catalyst for change. There is a danger remaining in could muddy the waters and allow U.S. citizens to believe they are contributing to resolving a global problem, when the opposite is the case.

It’s a novel argument for leaving the treaty—and one that, to be clear, remains a minority view. Almost every Congressional Democrat supports staying in Paris, as do more than a dozen House or Senate Republicans. More than 60 major companies—including Apple, Walmart, General Motors, 3M, Dupont, and Dow Chemical—all want the Trump administration to remain. So do Rick Perry, Rex Tillerson, and Gary Cohn, a White House economic adviser.

In addition, high-profile environmental groups across the political spectrum—including the Sierra Club, 350.org, and Catholic Climate Commitment—have all beseeched Trump to stick in the agreement.

Trump has promised he would deliver a final verdict on Paris this week. If he decides to leave, then a future president could still rejoin the treaty. Meanwhile, China, India, and the European Union have all said they will uphold their commitments and stay in the treaty. So it will be left to them—and U.S. voters in the 2020 election—whether the American exit from Paris dooms that agreement to the same fate as the Kyoto Protocol, or whether it becomes merely a short hiatus from a long-term global solidarity.