As the dust settled on the most serious challenge in decades to Russian President Vladimir Putin’s authority, Washington and its allies struggled to make sense of a head-spinning series of historic events that saw mercenary forces race up a highway to within 120 miles of Moscow on Saturday, then abruptly turn back after their leader, Yevgeniy Prigozhin, agreed to stand down and go to Belarus for an uncertain exile.

On Sunday, intelligence officials and diplomats – unsure if they had just witnessed an aborted coup or a thwarted mutiny – were left to parse official Kremlin statements and re-watch blurry videos posted on Telegram, the social network that Prigozhin has used to try to convince the Russian people that the war in Ukraine has been a strategic disaster led by incompetent commanders and political sycophants.

Publicly, U.S. officials have highlighted the possible benefits to Ukraine from the chaos in Russia. Secretary of State Antony Blinken said Sunday that the brief Wagner revolt, and how it was ultimately if tentatively resolved, showed “cracks in the facade” of Putin’s authoritarian leadership.

“Think about it this way: 16 months ago, Russian forces were on the doorstep of Kyiv in Ukraine, believing they would take the capital in a matter of days and erase the country from the map as an independent country. Now, what we’ve seen is Russia having to defend Moscow, its capital, against mercenaries of [Putin’s] own making,” Blinken said on NBC News’s “Meet the Press.”

“Certainly, we have all sorts of new questions that Putin is going to have to address in the weeks and months ahead,” Blinken added.

Officials in the United States and around Europe said they were unsure of what comes next and were concerned about the instability that could follow an effort by Putin’s rivals, including Prigozhin, to unseat the president at a vulnerable moment.

High on the list of questions policymakers are now putting to their intelligence analysts is whether Prigozhin has managed to shake the foundations of the Kremlin so strongly that Putin will feel compelled to sack top generals or ministers leading the war, as Prigozhin has repeatedly demanded.

More immediately, though, there’s another question: What just happened? One minute, Prigozhin had taken over a key military headquarters in the south running Russia’s war machine in Ukraine. The next, he had agreed to a truce brokered by Belarusian President Alexander Lukashenko, who’s more accustomed to playing second fiddle to Putin than intervening between warring factions.

“Why did it calm down so quickly, and how come Putin’s puppet Lukashenko got the credit?” asked one senior European diplomat, who like others spoke on the condition of anonymity to describe private discussions. “What impact will it have on Russia’s defenses, and are there going to be any personnel changes in the military leadership?”

Western officials also were unsure about what terms had been reached between Putin and Prigozhin to end the rebellion, and whether the peace would hold.

One Western intelligence official was skeptical that Prigozhin would remain quietly in Belarus, echoing speculation that he will either be killed or will continue to challenge Russia’s military establishment from abroad.

Watching the Wagner column head toward Moscow on Saturday, the official had predicted that Russian troops were unlikely to put up much resistance if they had been persuaded by his arguments that military leaders were to blame for the disastrous war. Prigozhin had said on social media that the Russian public hadn’t been told the truth about the setbacks in Ukraine, including about the extraordinarily high number of dead Russian troops. U.S. military figures have estimated casualties in the hundreds of thousands.

Bob Seely, a member of British Parliament who serves on the foreign affairs committee that has been investigating Wagner for two years, wondered if Putin feared his own military might not carry out his orders to stop Wagner forces from entering the capital. Earlier on Saturday, before the truce, Putin had described the Wagner fighters as traitors during a televised address to the nation.

“Would Putin have been able to order a lethal airstrike?” Seely asked. “Could Putin have actually killed Prigozhin on route? Or was it so bad for Putin that he couldn’t,” meaning that his grip on power was too tenuous? If Putin demanded that Russian forces attack and the answer was no, Seely said, “then Putin was in a desperate stage.”

“I can’t see this peace lasting,” Seely added, “because either Prigozhin is unstable and will continue to attack and seek to finish Putin off, or Putin will silence him in some way – financially, politically or physically.”

A Ukrainian intelligence official, who was likewise unsure why Prigozhin had stood down, saw signs that the mercenary leader may not have been confident in his prospects.

“I think he miscalculated in his expectations of military support,” the Ukrainian official said, taking a different view than some of his European counterparts. The revolt Prigozhin may have hoped for in Moscow failed to materialize, the official noted.

He added that there were indications Prigozhin may even have tried to phone Putin directly but received no answer. This sent a “very strong signal” to Prigozhin, the Ukrainian official believes: Putin would not simply acquiesce to his demands.

Another senior European diplomat said that allies hope to understand what Putin will do domestically in response to the unrest, especially with respect to any next steps in the stalemate on the Ukraine war front. The diplomat joked that even as Ukraine’s Western backers raced to decipher what had occurred, Russian intelligence probably did not have much of a head start.

“I think even Russian services are scratching their heads,” the diplomat said. “We will need some time to digest and also to see where things are moving.”

On the Sunday morning talk shows, Republican and Democratic lawmakers agreed that the events had weakened Putin and strengthened the United States’ resolve to continue supporting Ukraine. Later on Sunday, President Biden spoke with Ukrainian President Volodymyr Zelensky to discuss the current counteroffensive against Russia and committed to continue U.S. support for Ukraine, the White House said in a statement.

But intelligence officials cautioned that it remains to be seen whether Prigozhin’s challenge truly weakened Putin – and if the Russian leader believes it did. U.S. and Western analysts have long described Putin as isolated, surrounded by yes-men and blind to the challenges his forces face.

The Russian intelligence agency primarily responsible for understanding Ukraine, the FSB, failed to neutralize the government in Kyiv and foment any pro-Russian opposition to disrupt Zelensky’s hold on power, The Washington Post previously reported, based on intelligence material obtained by Ukrainian and other security services.

Putin has been misguided by advisers who may now try to convince him that he won in a standoff with Prigozhin, some officials said. That may only embolden the Russian leader, even if he is not as strong as he thinks.

Officials said that, in the near term, they will watch closely for any signs that Putin may replace two of the top leaders who have been the targets of Prigozhin’s Telegram rants: Defense Minister Sergei Shoigu and Gen. Valery Gerasimov, the chief of the general staff. Prigozhin had demanded an audience with both men as his forces marched across Russia.

Sacking the military bosses might not mean that Putin is giving in to Prigozhin, but rather that he realizes the Russian elite have lost confidence in their leadership. Prigozhin, some Western officials said, was only saying out loud what many around the Kremlin privately think.

“If Putin replaces Shoigu, it will not be because Prigozhin demanded it, but because Shoigu is weak,” the Ukrainian official said.

As for Prigozhin’s next move, U.S. and Western officials were keenly interested in whether the rift with Putin will prompt him to distance the Russian government from Wagner and withdraw support for its extensive operations in Africa and the Middle East, where the group offers security and military assistance and tactics on campaigns to influence governments facing rebellions or instability, in return for resource contracts such as gold in regions that are too unstable to attract Western corporations.

Though Prigozhin’s company seeks to turn a profit wherever it operates, its action often advances a Kremlin agenda and undermines Western interests. For those reasons alone, some Western officials believe Putin will probably continue supporting Wagner’s operations, but recent events may set back its future potential.

“I think Wagner will have their wings curbed heavily,” said a senior European intelligence official. That may come at a cost for Putin. “Prigozhin has been the gateway for Moscow in many places in Africa, and Moscow counts on African support more than ever,” the intelligence official said. But, he acknowledged, the Russian president has more pressing concerns, such as political survival.

“Faced with last weekend’s events, issues like Russian influence in Africa have a secondary weight for Putin.”