For two decades, an intractable divide defined international climate negotiations, where developed and developing countries were held to entirely different standards for monitoring, tracking, and reporting greenhouse-gas emissions. This model did not reflect reality; there was no way to account for the varying resources that different countries, on either side of the divide, had available for mitigating and adapting to climate change. One of the celebrated achievements of the Paris Agreement, in 2015, was that it finally knocked down the invisible wall, creating a new system that allowed for a range of emissions-reduction plans. Nearly every country on the planet became its own individual camp, responsible for crafting its own, nationally determined contribution to carbon neutrality.

The United States helped lead this overhaul, in part, by forging a partnership with China. “You had the biggest developed and the biggest developing countries able to help lead together,” Todd Stern, the chief climate negotiator under the Obama Administration, said recently. Stern famously took his Chinese counterpart, Xie Zhenhua, to a Chicago Cubs game during their courtship, travelled to Xie’s home town, and hosted a dinner for him at his house. China was willing to compromise, Stern said, because “the United States had a lot of credibility, not just internationally but because they were walking the walk at home.”

The situation, of course, has changed. At this year’s climate talks, in Katowice, Poland (officially referred to as a Conference of the Parties, or COP), which aimed to effectively activate the Paris Agreement, the U.S. State Department delegation was much smaller—and much more disconnected from the White House—than it had been under President Barack Obama. Diplomats are now working under a President who plans to withdraw the U.S. from the Paris Agreement in 2020, who has stopped providing any climate-related support for the most vulnerable countries, and who outright dismisses climate science. The Trump Administration “severely undermined their efforts,” Andrew Light, the senior adviser and India Counselor to the U.S. Special Envoy on Climate Change under the Obama Administration, told me.

For the second year in a row, the U.S. held a side event extolling the virtues of fossil fuels. An even more damaging moment—at least for the progress of the negotiations—came when the hundred and ninety-six nations present were hashing out the language for an official response to the most recent scientific report from the U.N.’s Intergovernmental Panel on Climate Change. The report, which described what 1.5 degrees Celsius of warming would mean for the world, said that in order to avoid the most catastrophic climate impacts, we have a decade to revolutionize our global energy system. If climate change were an asteroid, this was the final warning before it hit. But the U.S.—along with Saudi Arabia, Kuwait, and Russia—refused to say that they “welcomed” the report, insisting instead that the statement describe their reception of it as “noted.” The final text, which was released on Saturday evening, “welcomed” the report’s “timely completion.”

The talks began last week, and were scheduled to conclude on Friday, the deadline for the final agreement. The main task was to create a Paris Agreement rulebook—standardized guidelines for how countries will monitor, track, and report their reductions in greenhouse-gas emissions. The conference leaders also wanted to see a text that somehow signalled that countries would return to the next round of major negotiations, in 2020, with more ambitious nationally determined contributions. Negotiations dragged on through Friday night and all day Saturday. It was “hard to find a key issue that wasn’t a struggle,” Light told me. “While there are always a lot of moving parts in these negotiations, normally there are two to four prominent issues that slow things down and make it hard to finish.” As late as Thursday, he said, “there were still nine or ten.”

At a political level, the lack of U.S. leadership was a major impediment. “You don’t have the whole power of the U.S. machinery, which can play a critical role when moving in the right direction,” Jake Schmidt, the managing director for the Natural Resources Defense Council’s international program, told me. “Under Obama, it was all hands on deck. In Paris, the Ambassadors were calling each country. The State Department would have, say, our Ambassador in Delhi go to the foreign-ministry office, saying ‘Hey, this is an important priority for the U.S.’ ” Or, Schmidt continued, Todd Stern or John Kerry or President Obama “would have been on the phone with Xi Jinping saying, ‘C’mon, we agreed to this, let’s do it.’ ”

The European Union, which recently announced that it would achieve carbon neutrality by 2050, played a somewhat comparable role. But domestic problems interfered. The French have been in the middle of a political crisis sparked by climate policy, and Britain is leaving Europe. Some observers hoped that Germany, which is not on track to meet its 2020 climate target, would set a date for phasing out coal consumption, but it appears that won’t happen until next year. Without U.S. leadership and influence, the old developed-vs.-developing dichotomy crept back in. There was “a lot of push this year from a number of developing countries to basically re-bifurcate these things,” Stern said in a recent conversation with David Victor, the co-chair of the Cross-Brookings Initiative on Energy and Climate. “It’s a big fight.”

Since the I.P.C.C. report was published, a number of countries are now looking for ways to achieve the total emissions reductions necessary to stop warming at two degrees Celsius. But, like Germany, the majority of Western countries are not even moving at a pace to meet their Paris targets, which would allow more than three degrees of warming. Last week, just after the conference began, a group of scientists published a paper projecting that global carbon emissions for 2018 would increase by nearly three per cent. Regardless of the outcomes of this year’s talks, the fact is the world remains on track to suffer the worst-case scenarios that the I.P.C.C. has modelled for the rest of the century.

On Saturday night at nine-thirty, consensus was finally reached and the concluding plenary began. The result is either a failure or a relative success, depending on whom you ask. Many activist observers believe that human rights and climate justice were not addressed in any meaningful way. But for Light and other Paris alumni, the rulebook came out strong enough, with several key elements that properly reflect the Paris Agreement. Unlike the bad old developed-vs.-developing days, every country will be subject to a single set of emissions-reporting rules—and, eventually, the same level of transparency. But it will permit countries to self-identify their economic-development status. “This will make it incumbent on China not to identify itself in the same category as Bangladesh,” Light said. The poorest countries, those that will have the hardest time monitoring their emissions, will, however, have more flexibility and time to meet the universal standard.

In the end, China was able to “quietly and skillfully” exert a greater influence on the meeting’s outcome, Light said. “You can’t compete with China unless you’re on the field.” President Xi Jinping will push forward with his government’s clean-energy agenda—building massive solar and wind farms, investing in nuclear power, and cleaning up his country’s coal fleet—but only through the lens of what’s in China’s interest. “It’s not so much that they are concerned about global climate change, although that may be coming,” Victor said. “It’s more because they are concerned about building local industries, and especially about cleaning up the air locally and regionally.” The country remains the largest developer of coal in the world, although that development is increasingly happening outside its borders.