LONDON - When the jet believed to be carrying Yevgeniy Prigozhin and several top commanders of the Wagner paramilitary group fell from the sky west of Moscow on Wednesday, its destruction sent a terrifying message to Russia's elite, even though the cause of the crash may never be conclusively known.

"Anyone who displays disloyalty will be seen by the state as an enemy that needs to be liquidated," one well-connected Moscow businessman said. "Everyone will believe that this was carried out on the orders of the czar. We may never know whether this is true or not. But it has frightened everyone."

The downing of Prigozhin's plane has bolstered Vladimir Putin's hold on power, at least in the short term, officials and analysts said, restoring a reputation for a ruthlessness that had been undermined by his hesitant response to the Wagner mutiny in June and puzzling truce with the renegade warlord.

At the same time, the broader sequence reflects a further descent into Mafia-style dysfunction for the Russian state that Putin has shaped over two decades in office - one that seemed paralyzed during Prigozhin's march on Moscow and now will be suspected of having dealt with his alleged treason not through an arrest and trial but by sending a jet plunging to earth with nine other passengers aboard.

U.S. officials said they are considering the possibility that the plane was destroyed by an explosion aboard, noting there was no sign of a missile launch targeting the Embraer business jet.

Putin's agreement to lift criminal charges against Prigozhin over his attempted mutiny in June, allowing him safe passage to Belarus and then even granting him a Kremlin audience, had shattered the Kremlin's carefully crafted image of a ruthless president and invited questions over whether others - or even Prigozhin - could mount a fresh challenge.

But on Thursday, Russian business executives said that now, more than ever before, they were reluctant to raise their voice publicly against Putin's invasion of Ukraine. Many among Russia's wealthiest have been privately critical of the handling of the war, and some had been weighing making less guarded public comments, although nothing as intemperate as Prigozhin's criticism of Russia's military leadership and how it has directed the campaign.

But after an apparent act of such calculated and brazen violence, they fear that even the mildest or most constructive criticism could invite savage retribution\.

"I don't think anyone wants to speak out against the war after this," said one Russian billionaire, who, like others, spoke on the condition of anonymity for fear of being targeted by the state. "Everyone should now understand what the risks are. They are gigantic," he said, adding he was taking extra measures to boost his own security.

Russia experts agreed that Prigozhin's fate will stamp out any remaining impulse among Russia's elite to challenge Putin. "The cost side of doing so has gone up spectacularly," said Eric Ciaramella, a former CIA Russia analyst who is now a senior fellow at the Carnegie Endowment for International Peace. "Before it was, 'Maybe we can't get enough people to make it work.' Now it's, 'If I step my toe over this line, I'm going to get blown up in the sky.'"

"This is a strong message for the Russian elites that whoever is independent or pretends to be independent will be killed," a senior Ukrainian official said.

A new climate of fear in Russia will further entrench Putin's grip on power. But it could also eradicate the few remaining independent channels of information reaching Putin about the direction of the war, leaving the Russian president ever more isolated, experts said.

Before his attempted mutiny, Prigozhin had launched a series of increasingly vitriolic diatribes against corruption in the Russian Defense Ministry and blaming its leadership for ammunition shortages and setbacks in the military campaign. He had previously directly confronted Putin over the military's handling of the war, and on the eve of the mutiny, even challenged Putin's rationale for launching the invasion, claiming the Russian president had been duped by greedy Defense Ministry officials and oligarchs.

Prigozhin's criticisms of the Defense Ministry leadership had found support among Russia's security and military establishment, according to European security officials, and reflected deepening fissures among the elite over the conduct of the war.

One senior member of Russian diplomatic circles said these differing views remained, with some calling for a quick end to the war and others calling for the campaign to be expanded with even more destructive and indiscriminate targeting. But he added that it was no longer clear who would voice calls for more radical action in Prigozhin's absence. "It's clear there are problems inside the Russian army," he said. "It would be difficult to imagine that over these few months after the public speeches of Prigozhin these problems could have been solved."

Prigozhin was also supported by a new generation of military bloggers, who had gained Putin's ear as he sought out alternative sources of information about the invasion's progress. But according to Kremlin-connected political analyst Sergei Markov, a new era of "military censorship" is set to begin, while Prigozhin's top-ranking supporters among the military, such as air force commander Gen. Sergei Surovikin, are being removed from their posts. "This is clearly the policy of the Defense Ministry," Markov said.

Prigozhin's challenge had taken Putin's presidency into uncharted territory, marking the first time he had to counter a powerful member of his own inner circle who had built deep ties across Russia's security establishment over a decade. His Wagner Group had often acted as a shadow arm of the Russian state, building influence and running paramilitary operations across the Middle East and Africa, before officially taking a vanguard position in the war in Ukraine.

The spectacular manner in which Prigozhin apparently was killed appears to mark a ruthless escalation of Putin-era tradecraft, according to Western intelligence officials and Russia experts.

Prigozhin was among 10 passengers - including presumably innocent crew members - on an aircraft whose plummeting fuselage might have endangered dozens or hundreds of ordinary citizens in the plane's flight path.

"They didn't care that they got the crew and that it could have put people on the ground at risk," said a former U.S. intelligence official. "It was extremely reckless."

Since Putin took power two decades ago, other defectors, accused traitors and political adversaries have been targeted in plots known for their baroque methods and seeming insouciance about the amount of evidence left pointing toward Russia, as if that lack of concern about fingerprints was also part of the message.

Alexander Litvinenko, a former Russian Federal Security Service officer who defected to England and became a vocal critic of Putin, died in 2006 after drinking tea laced with radioactive poison in a plot that the British government concluded had "probably" been directly approved by Putin.

Boris Nemtsov, a physicist turned crusader against alleged corruption surrounding Putin, was killed while crossing a bridge near the Kremlin in 2015 with four shots fired into his back.

The attempted poisoning in 2020 of Putin's main political nemesis, Alexei Navalny, involved a toxin that is not known to have ever been produced anywhere other than Russia. He survived only to be imprisoned indefinitely.

Prigozhin stood apart from these and other previous targets mainly because of how much wealth and power he had amassed during the Putin era and how closely he had aligned himself with the Russian leader.

The two months between Prigozhin's aborted mutiny and his killing could be a reflection of the time the Kremlin needed to neuter Prigozhin's organization, while the Wagner Group's operations were wound up and handed over to paramilitary groups owned by business executives deemed more loyal to the Kremlin, experts said. "Eliminating the CEO of the company you absorb on day one is a stupid move," said Alexander Gabuev, director of the Carnegie Russia Eurasia Center.

But Prigozhin's apparent two-month stay of grace before the final denouement of his attempted mutiny failed to impress fearful Russian business executives. "Two months is not a very long time in a person's life," the Russian billionaire said. "We all know Putin never forgives such things. That this was going to happen was always clear."