In the list of campaign promises from Donald Trump, the one about the war in Ukraine stood out for the number of times he repeated it—“I’ll have that thing ended in 24 hours”—and for the undeniable way he failed to deliver. His self-imposed deadline, of course, passed in January, and the president has since admitted that the belligerents proved much harder to reconcile than he had expected. Still he continues to try. But his efforts have not resembled a peace process so much as a pendulum, swinging between the Russian and Ukrainian positions, with occasional stops in the middle to express frustration over the whole affair.

The latest swing to the Russian side this month has been a doozy. Last week, the White House embraced a 28-point “peace plan” stuffed with the Kremlin’s demands, and Trump gave Ukraine five days to accept it. The task of delivering the ultimatum fell to Dan Driscoll, the U.S. Army secretary, who arrived in Kyiv just as the plan leaked to the media. Its provisions looked to many Ukrainians like a set of demands for their capitulation. But their president, Volodymyr Zelensky, did not turn down the offer from his American guests. “We thought we were going to try to open the door, but the door was open,” a U.S. official said of Driscoll’s visit. “They were ready to talk.”

So were the Americans. As they went over the details, Trump’s Thanksgiving deadline fell away, as did several of the plan’s most onerous provisions. Negotiators whittled the list down to 19 points during a round of talks this weekend in Geneva, and Trump is dispatching another one of his envoys to Moscow to present the amended version to Vladimir Putin. Its fate now depends on the willingness of the Russian president to compromise, and that is where Trump’s peace efforts have so far hit a wall.

The Russians have signaled that they will not budge from their core demands, the same ones Putin spelled out to Trump during the August summit, in Alaska. If they hold firm, then the whole exercise will simply bring the peace process back to its default state of deadlock, leaving Ukrainians to wait once again for some respite from Russian attacks. Even as Driscoll made his pitch in Kyiv on November 19, a Russian strike on an apartment building in the western city of Ternopil killed at least 31 people, including six children, and wounded another 94. The attack brought the total death toll from Russia’s long-range strikes to more than 550 so far this year.

Trump’s latest attempt to end this carnage could be seen as a negotiating tactic, intended to wear away at Moscow’s recalcitrance over time. But most of Trump’s allies in Europe believe this strategy will fail unless the White House accepts two basic things about the war: First, Russia started it. And second, Ukraine and its allies need to force Russia to stop it. That’s what the Europeans have spent the past three and a half years trying to do, and they’re convinced that they can ultimately succeed. “We already had a sustainable plan,” a senior European diplomat involved in implementing it told me. “We don’t understand why the U.S. turned away from it. Clearly, somebody convinced Trump that Ukraine is losing.”

Before the Ukrainians received Trump’s latest ultimatum, they did not appear to be losing the war. On the contrary, fall brought a rare moment of optimism for Zelensky and his aides. Throughout the summer, Russian forces failed to make substantial gains along the front. Ukraine held the line through the mass deployment of combat drones, which forced the Russians to take enormous casualties in exchange for small chunks of territory.

Ukraine’s impressive fleet of long-range drones also pounded Russian oil refineries throughout summer and fall, causing fuel shortages across the country. One of the Ukrainian officials behind this campaign of deep strikes into Russia described it as a key to winning the war. “We cannot defeat them on the front lines. That’s true,” he told me. “But we can defeat them in other ways. They have 40 refineries around the country. We know where they are. One at a time, we can turn out their lights.”

Such theories of victory rely on a simple premise: Ukraine, with help from its allies, can win a war of attrition against its vastly larger and more powerful enemy. This belief requires an underlying faith in the frailty of the Russian economy, the Russian political system, or both. The available facts, however, do not suggest either one will collapse anytime soon.

Under the weight of intense sanctions imposed in 2022, Russia’s economy contracted slightly but soon returned to growth, thanks largely to the dose of steroids administered by military spending, which is estimated to stand at more than $150 billion per year. That is roughly equivalent to the size of Ukraine’s entire GDP before the full-scale invasion began. In Russia, “there are no signs that the worsening economy is capable of stopping the war,” Oleg Itskhoki, a Harvard economics professor who studies Russia, concluded last month. “In principle this could go on for a long time,” he told the New Times, one of Russia’s last remaining independent news outlets.

Even Zelensky does not believe that, over the long term, Ukraine can outlast Russia in a war of attrition. But he sees no clear options other than to surrender or to continue fighting, and his people, exhausted as they are, have consistently made their preference clear. Although polls have shown a growing desire among Ukrainians to negotiate an end to the war, solid majorities continue to reject the idea of ceding large amounts of land to Russia in exchange for peace.

Public opinion has thus pressured Zelensky to find new ways to carry on the fight. In early September, he announced that Ukraine’s expanding military industry now produces more than half of the weapons used at the front. Even if the United States cut off military aid, Ukraine’s armed forces could use these weapons to hold back the enemy. The risk of such a cutoff seemed remote this fall. Support for Ukraine has grown stronger across the U.S. political spectrum; nearly three-quarters of Republicans who participated in a Harvard/Harris poll last month said that they want the U.S. to continue sending weapons to Ukraine; 86 percent said that they want to impose more sanctions on Russia to force an end to the war.

As Russian advances stalled along the front line, morale inside Zelensky’s circle rose to a level his team had not seen in more than a year. “He’s come alive again with the hope that we can really win the war,” one of his closest aides told me in late September. “And yes, he’s infected the team with this idea.”

He also seemed to infect Trump. On the sidelines of the United Nations General Assembly, Zelensky made his case that Trump should unleash a fresh wave of U.S. sanctions that might force the Russians to negotiate. According to one person briefed on the meeting, Zelensky took out a map of the battlefield and pointed to the region of Donetsk. He claimed that Ukrainian forces were on the verge of encircling a large group of Russian soldiers in that region, near the front-line city of Pokrovsk. Such a rout would humiliate the Kremlin, demoralize the Russian military, and, Zelensky argued, deepen the war fatigue among Moscow’s elites.

The presentation struck a chord. In a post on social media, Trump declared that Ukrainians may be able to “take back their Country in its original form and, who knows, maybe even go further than that!” The prediction went well beyond even the rosiest forecasts of military experts, because it would entail Ukraine retaking all of its occupied territory, including Crimea, and then potentially conquering chunks of Russia itself. Such an outcome would be possible, Trump suggested, once the Russian people “find out what is really going on with this War.”

Less than an hour after the post hit Truth Social, Zelensky gathered a group of reporters in a windowless meeting room beneath the UN headquarters in New York City. We all wanted to know how he had changed Trump’s mind, but Zelensky declined to discuss the details. He only expressed relief that his arguments had swayed his most important ally. “This post is a big shift,” he said. “Trump is a game changer.”