Leaked US-Russia call sets off global game of clue: Who did it—and why?

Around the world, everyone from diplomats to amateur sleuths chased the usual questions of means and motive. Who has the capacity to eavesdrop on a cellphone chat between top Russian and American officials? And who would benefit the most from leaking the conversation?

Was it a European intelligence agency, hoping to sabotage what many European capitals see as an emerging cease-fire plan tilted in Russia’s favor? That’s the theory top Russian officials quickly suggested on Wednesday.

Was it the Russians themselves—an element within the Russian government or oligarchy that is profiting from the war and wants it to continue? That’s the theory raised by some European officials. One suggested it could be a Russian power play to show Witkoff was in their pocket.

Or was it someone else, like a rogue member of a U.S. government agency who might also worry that President Trump could press Ukraine into signing a deal that favors Russia?

“Everyone is trying to figure it out," said Emily Ferris, a Russia expert at the Royal United Services Institute, a London think tank. “This has been a messy couple of weeks, and this just adds to the obfuscation and lack of clarity—mistrusting everything that comes out of all countries."

The transcript of the call between Witkoff and Yuri Ushakov, Russian President Vladimir Putin’s top foreign policy aide, was published late Tuesday by Bloomberg News. The news agency made sure not to give any clue as to its sources: the article didn’t carry a byline or a dateline.

A senior Trump administration official said he believed the call was leaked by a foreign intelligence agency, and that the target wasn’t Witkoff, but Ushakov, who was also recorded in a second conversation with another Kremlin envoy, Kirill Dmitriev.

A European security official said that dozens of countries around the world had the technology to listen into Ushakov’s conversations, as the Kremlin official was using an open cellphone line.

His main suspect? Likely to be a European country, he said, but didn’t know who exactly. Then again, he added, Russia couldn’t be ruled out because there are divisions and infighting over Dmitriev’s role as a Kremlin go-between.

The Oct. 14 call between Witkoff, Trump’s peace envoy for both Gaza and Ukraine, and Ushakov offered a glimpse into the origins of a 28-point peace plan that emerged in recent days and was widely viewed as friendly to Russia.

During the call, which came at a time when Trump was increasingly blaming Putin for not wanting to end the war, Witkoff suggested to Ushakov that the Russian leader call Trump to patch things up and get peace talks restarted. He appeared to coach his counterpart to make sure Putin started the conversation by lavishing praise on Trump for the Gaza cease-fire plan.

“From that, it’s going to be a really good call," he said, according to a transcript first published by Bloomberg.

Putin and Trump did have a long conversation later that week, a chat that ended with a win for Putin: During the following day’s visit to the White House by Ukrainian President Volodymyr Zelensky, Trump turned down the Ukrainian’s request for long-range Tomahawk missiles and has since put the Ukrainians on the diplomatic defensive. The Ukrainians say that pressing Russia on the battlefield is the only way to force them to meaningful peace talks.

Trump, who has set aside normal diplomatic channels to strike deals through informal talks using brokers like Witkoff and his son-in-law Jared Kushner, said he didn’t see anything wrong with the Witkoff conversation, saying it was a normal part of negotiations.

Some Republican lawmakers, however, criticized Witkoff’s role and said the conversation revealed he was too cozy with the Russians.

A senior Ukrainian official came to Witkoff’s defense. “We don’t believe that Witkoff is playing on the Kremlin side," Mykhailo Podolyak, a Ukrainian presidential adviser, in comments to Ukrainian media confirmed by his spokesman.

On Wednesday, Ushakov told Russian state television that whoever leaked the call was likely trying to interfere with Russia’s peace talks with the U.S.

“They’re doing it to interfere with us, it’s unlikely that they’re doing it to help improve relations [between Russia and the U.S.]," he told a Russian state television reporter.

He said he didn’t know who leaked the call, but said it wasn’t the Russians themselves. “I don’t know, they’re leaking it, they’re listening in, but it’s not us."

Ushakov also criticized European countries that had raised objections to the original 28-point peace plan. “The Europeans are interfering in the Ukraine peace process in a completely unnecessary way," he said.

Ushakov suggested during one interview with a Russian news site that some conversations happen over WhatsApp, an encrypted messaging app owned by Meta, and that could allow people to eavesdrop.

This isn’t the first leak involving diplomats and Ukraine. In early 2014, around the time that Moscow annexed Ukraine’s Crimea peninsula, Russia was widely believed to be behind a leaked tape that had top U.S. officials discussing who should lead a new pro-Western government in Ukraine.

The tape also exposed strains between the U.S. and Europe over what was happening in Kyiv, with then-Assistant Secretary of State Victoria Nuland expressing frustration at the European Union’s less activist role. “F— the EU," she was taped saying.

Years later, there is something of a role reversal: Europe is now much more hawkish than the Trump administration in trying to prevent a revanchist Russia from swallowing all of Ukraine and trying to unravel the postwar trans-Atlantic security architecture.

“The Americans and Europeans are coming at this from two different angles," said Ferris. “Europe sees Russia rearming, and are worried about anything that allows Russia to regroup, learn lessons and up their defense complex to have another go at Ukraine or test NATO boundaries. The Americans are thinking much more short-term—get the peace process over the line, get a cease-fire, get Ukraine back on its feet and cobble together some sort of cold peace for another year or two."

No matter who leaked the conversation, it added to a sense of chaos and uncertainty around the war and diplomacy that will likely be fine with Russia, Ferris said. “This is a fantastic place for the Russians to be. They need to do very little here. All their responses show they don’t feel much need to hurry things along," she said.

No matter who recorded the call, or leaked it, it may not end up mattering very much. Russia’s Deputy Foreign Minister Sergei Ryabkov said Wednesday that Russia’s goals from its “special military operation" in Ukraine hadn’t budged.

Write to David Luhnow at david.luhnow@wsj.com and Thomas Grove at thomas.grove@wsj.com