Jamie Dettmer is opinion editor and a foreign affairs columnist at POLITICO Europe.

Another round of U.S.-brokered Ukraine talks commence today in Abu Dhabi.

The overall outlook remains no less bleak for Ukraine, as it inches toward the fourth anniversary of Russia’s war. Yet there are signs that what comes out of this week’s face-to-face negotiations may finally answer a key question: Is Russian President Vladimir Putin serious?

On the eve of the planned two-day talks, Russia resumed its large-scale air assault on Ukraine’s battered infrastructure after a brief weekend hiatus. Striking cities including Kyiv, Dnipro, Kharkiv, Sumy and Odesa overnight with 450 drones and 71 missiles, including ballistic, Russia hit the country’s energy grid and residential houses as temperatures dropped below -20 degrees Celsius.

“Putin must be deprived of illusions that he can achieve anything by his bombing, terror, and aggression,” pleaded Ukraine’s frustrated Minister of Foreign Affairs Andrii Sybiha. “Neither anticipated diplomatic efforts in Abu Dhabi this week nor his promises to the United States kept him from continuing terror against ordinary people in the harshest winter.”

According to U.S. President Donald Trump, those promises included refraining from targeting Kyiv and other major cities for a whole week during a period of “extraordinary cold.” But no sooner had Trump spoken than Kremlin spokesperson Dmitry Peskov warned the break would only last a weekend.

That’s hardly an auspicious launchpad to negotiations, and has many Ukrainian politicians arguing that Russia is merely going through the motions to ensure it doesn’t end up on the wrong side of an unpredictable U.S. leader — albeit one who seems inordinately patient with Putin, and much less so with Ukrainian President Volodymyr Zelenskyy.

Not that Ukrainians had put much store in a week-long “energy ceasefire” to begin with. A vicious war has taught them to expect the worst.

“Unfortunately, everything is entirely predictable,” posted Zelenskyy adviser Mykhailo Podolyak on Tuesday. “This is what a Russian ‘ceasefire’ looks like: during a brief thaw, stockpile enough missiles and then strike at night when temperatures drop to minus 24 Celsius or lower, targeting civilians. Russia sees no reason whatsoever to stop the war, halt genocidal practices, or engage in diplomacy. Only large-scale freezing tactics.”

It’s difficult to quibble with his pessimism. Putin’s Kremlin has a long track record of using peace talks to delay, obfuscate, exhaust opponents and continue with war. It’s part of a playbook the Russian leader and his lugubrious Minister of Foreign Affairs Sergey Lavrov have used time and again in Ukraine, and for years in Syria.

Nonetheless, according to some Ukrainian and U.S. sources familiar with the conduct of the talks, there are indications that the current negotiations may be more promising than widely credited. They say both sides are actually being more “constructive” — which, admittedly, is an adjective that has often been misused.

“Before, these negotiations were like pulling teeth without anesthetic,” said a Republican foreign policy expert who has counseled Kyiv. Granted anonymity in order to speak freely, he said: “Before, I felt like screaming whenever I had to see another readout that said the discussions were ‘constructive.’ But now, I think they are constructive in some ways. I’m noticing the Russians are taking these talks more seriously.”

Some of this, he said, owes to the skill of those now leading the Ukrainian team after the departure of Zelenskyy’s powerful former chief of staff, Andriy Yermak. Among the smartest and most able are: Yermak’s replacement as head of the Office of the President and former chief of the Main Intelligence Directorate Kyrylo Budanov; Secretary of the National Security and Defense Council Rustem Umerov; and Davyd Arakhamia, who heads the parliamentary faction of Zelenskyy’s ruling Servant of the People party.

“I am noticing since Davyd got involved … there’s been a noticeable improvement with the Russian negotiators. I think that’s because they respect them — especially Davyd — and because they see them as people who are living in reality and are prepared to compromise,” the expert explained. “I’m cautiously optimistic that we have a reasonable chance to end this conflict in the spring.”

A former senior Ukrainian official who was also granted anonymity to speak to POLITICO was less optimistic, but even he concurred there’s been a shift in the mood music and a change in tone from Russia at the negotiating table.

Describing the head of the Russian delegation, chief of the Main Directorate of the General Staff of the Russian Armed Forces Igor Kostyukov, and Military Intelligence officer Alexander Zorin as practical men, he said neither were prone to giving long lectures on the conflict’s “root causes” — unlike Lavrov and Putin. “The Russian intelligence officers have been workmanlike, digging into practical details,” noted the former official, whom Zelenskyy’s office still consults.

He hazards that the change may have to do with the Kremlin’s reading that Europe is getting more serious about continent-wide defense, ramping up weapons production and trying to become less dependent on the U.S. for its overall security.

“A peace deal, an end of the war, could take a lot of the momentum out of this — European leaders would have a much tougher time selling to their voters the sacrifices that will be needed to shift to higher defense spending,” he said.

Of course, Russia’s shift in tone may be another attempt to string Trump along. “Putin has almost nothing to show for the massive costs of the war. Accepting a negotiated settlement now, where he cannot claim a clear ‘win’ for Russia and for the Russian people, would be a big problem domestically,” argued retired Australian general Mick Ryan.

Whatever the reasons, what emerges from Abu Dhabi in the coming days will likely tell us if Putin finally means business.