It’s official: The Trump administration will pull the United States out of the Paris climate change agreement.

“In order to fulfill my solemn duty to protect America and its citizens, the United States will withdraw from the Paris climate accord,” President Trump said in a Rose Garden statement on Thursday afternoon.

The move puts the United States in rare company. The only countries that aren’t part of the Paris agreement are semi-authoritarian Nicaragua and Syria, where Bashar al-Assad’s regime is too busy slaughtering its own people to worry about climate change.

Think about that for a second. The United States, the world’s sole superpower and architect of the international order, is reportedly going to quit an agreement that shares near-universal support globally. Even North Korea is on board.

This isn’t just a random piece of trivia. It speaks to the major, major implications that Trump’s decision has for America’s strategic position around the world.

While the president cast the Paris agreement as fundamentally unfair to the United States — "at what point does America get demeaned, at what point do they start laughing at us" — it actually is part of a web of interconnected agreements that sustain America’s dominant global position in the world. Isolating the US in this fashion sends an extraordinarily strong signal to other major powers that the US cannot be trusted to act on its international commitments, or even to work within international organizations at all.

Washington depends on other countries trusting it to stay in agreements to maintain agreements that preserve American strength. America’s status as sole superpower persists in part because other powerful countries, like France and Germany and Japan, think that American leadership is in their best interests. Every time Trump suggests these countries can’t count on the US anymore — through actions like pulling out of Paris and insulting NATO allies in his foreign trip — he threatens the very foundations of America’s global power.

“It’s death by a thousand cuts — and I don’t know what cut we’re at,” says William Wohlforth, an international relations professor at Dartmouth College.

So while the key issue when it comes to Paris is climate change itself — whether the world’s countries can continue to work together effectively to prevent catastrophic warming — it’s also a vital issue for America’s position in the world. The Trump administration either doesn’t understand this or doesn’t care.

“Trust takes a long time to build — and you can lose it very quickly,” Paul Musgrave, a scholar of US foreign policy at the University of Massachusetts Amherst, says.

The counterintuitive connection between the Paris climate agreement and US power

Paris isn’t a treaty, or formal international law. It’s a nonbinding agreement, one that commits countries to taking a set of unspecified steps to keep global warming below 2°C. Actually meeting that goal is nigh impossible, but Paris is essentially designed to shame and prod countries into at least making a good-faith effort to seriously reduce their CO2 emissions and build up their green energy capabilities.

This flatly cannot work without the United States. As the world’s largest economy and second-largest CO2 emitter (China is No. 1), US cooperation with Paris is vital to convincing other countries to make a serious effort to meet their targets. If the US isn’t trying, the logic goes, then why should we? For this reason, the Obama administration played a major role in writing the original text of the Paris agreement, shaping it such that its terms were acceptable for American interests.

Pulling out of the agreement at this point suggests that the US doesn’t care about climate change anymore, or about the potentially catastrophic consequences for the planet. But it also sends a broader signal that the US considers its obligations to be optional. That the US leadership can no longer be trusted to adhere to agreements on issues of vital concerns for other countries — even when it helps set the terms of the agreements itself.

“We’re talking about undoing something that was the project, the signal accomplishment of a whole group of countries — on more or less on a whim,” Musgrave says.

The problem with that, though, is that the entirety of America’s global strategy is founded on the opposite perception. It depends on other countries trusting the US to abide closely enough to its on-paper agreements that it won’t pose a threat to them.

Consider American’s staggeringly large military. The US spends more on defense than every other major economy combined (meaning Japan, Germany, Russia, France, the UK, India, and Brazil). It also has more than 27 times as many foreign bases as every other nation combined. Historically, this kind of extraordinary military advantage would lead other countries to counterbalance, to build up their own militaries to match the potential threat emanating from Washington.

Yet there’s no worry among French or British leaders that the US is going to invade their countries. Other developed countries, like South Korea and Germany, even allow the US to maintain massive bases on their soil.

That’s because the US has credibly committed to ally indefinitely with these countries. America is obligated to do more than just not invade Germany; it’s pledged to actually defend Germany in the event of an attack. These kinds of agreements render extraordinary amounts of US dominance over other countries basically acceptable to major powers that might otherwise be rivals.

You can see a similar effect play out in nonmilitary parts of world politics, like the economy. The US is the only country to have veto power over major decisions at both the International Monetary Fund and the World Bank, giving it tremendous power over global cash flows. World Trade Organization negotiating rules give the US disproportionate leverage over the rules governing global trade.

Yet other countries seem to be basically fine with that: They treat the IMF, World Bank, and WTO as the basic arbiters of how the global economy functions. The reason why, again, is that these organizations bind the US too. If a WTO ruling on a trade dispute goes against the United States, the US has committed to accepting that. These rules constrain America enough, and benefit all the weaker countries in enough concrete ways, that everyone is willing to accept their basic contours. This helps preserve America’s dominant place in the global hierarchy indefinitely.

“By binding itself to other states within a system of rules and institutions, the leading state makes its power more acceptable to other states, creating incentives for support rather than opposition,” Princeton professor G. John Ikenberry writes in Liberal Leviathan, his influential book on US power.

Leaving Paris undermines faith in this system to operate as promised. The US has made a major commitment to other countries to agree to a certain set of rules for tackling a shared problem, climate change. It has now decided to quit those rules, and simply do whatever it wants. What’s to say the US won’t do the same thing again on something else — abandon a NATO ally, say, or simply ignore an unfavorable WTO ruling?

“There’s a lot of trade-offs that happen between one policy area and another,” Wohlforth says. “Once you’re backing out of too many things, aside from the thing you’re negotiating, you can end up reducing your leverage.”

Leaving the Paris climate deal sends a signal that all US commitments are optional — and that’s why it’s so dangerous

Now, US action in one specific policy area typically doesn’t undermine the entire international system. President Obama’s failure to follow through on his threat to use force in Syria, for example, didn’t affect anyone’s perception of American commitment to NATO.

And the US has a broad reservoir of trust when it screws up, even badly. In the runup to the 2003 Iraq War, for example, the Bush administration shrugged off a lack of United Nations Security Council authorization and dismissed allies who opposed the war as “old Europe.” This damaged trust in the US’s ability to abide by the rules, and thus damaged the entire international order. But subsequent diplomacy under both Bush and Obama aimed at restoring Western allies’ faith in the US managed to mostly undo the damage.

Paris is different. And it’s different because Trump is different.

This is a president who describes his foreign policy as “America First,” and who warned against “the false song of globalism” in his most comprehensive foreign policy speech during the campaign. This is a president who has repeatedly questioned the importance of the NATO alliance, and who refused to commit to defending these allies at the organization’s recent summit. This is a president who declared that the WTO is a “disaster,” and whose advisers prepared a report proposing to simply ignore unfavorable rulings from the organization.

In short, Trump seems actively hostile to the international political order. Given that context, every little thing he does to signal lack of interest matters.

“If you had an administration that was not doing all of these other things that threatened to have the same effect ... the US [order] could easily bear singling out the Paris agreement,” Wohlforth says. “In this case, we are following a string of these kinds of decisions. It’s in that context that you’re worried: What’s going to be the straw that’s going to break the camel’s back?”

Wohlforth doesn’t think that Paris is that straw; rather, it’s one more straw on the pile when there’s already a ton of them. Global trust in US leadership isn’t yet at a breaking point, but it’s so low that it can ill afford another stressor. We don’t know exactly what the breaking point will be, but we do know that quitting a major international agreement on a serious global problem brings us closer to it.

“[Withdrawing from Paris] is not cheap talk,. [Leaving Paris] is sending a signal that you’re not even going to send lip service to coordinating on global issues,” Musgrave says.

We’re already seeing some signs of such a backlash. At a much-commented-on speech last weekend, German Chancellor Angela Merkel declared that Germany needed to take a more assertive role in global politics, because “recent days have shown me that the times when we could rely completely on others are over to a certain extent." The subtext — that Germany couldn’t rely on the US anymore — was unmistakable, coming as it did on the heels of meetings with Trump at the NATO and G7 summits (the G7 is an organization made up of seven large advanced economies).

Less commented on, however, was the fact that Merkel specifically cited her chats with Trump on climate change as a reason for this pronouncement.

“We Europeans must really take our fate into our own hands,” she said. "It became clear at the G7, when there was no agreement [on climate] with the USA, how long and rocky this path would be.”

Now that “no agreement” has turned into the US actively undermining global efforts to combat climate change, Merkel’s argument appears to be supercharged.

The consequences of recklessly disregarding allied opinion and international institutions may not be felt tomorrow. But in the long run, they could permanently undermine the core foundations of American power — leading other countries to put less faith in US-led institutions, and seek alliances and structures that don’t depend on the US. That would by necessity limit US influence over major powers in the world; Musgrave goes so far as to call it “hegemonic suicide.”

We’re a long way from that scenario, something that was unthinkable prior to the Trump administration. But the more Trump does stuff like quit the Paris agreement, the weaker America is likely to get in the long run.

That’s some notion of “America First.”