When he launched the full-scale invasion of Ukraine in 2022, Russian President Vladimir Putin apparently believed Russian forces would topple the government within weeks and restore Moscow's dominance over the country after 30 years of independence.
Putin was mistaken, and the war he started rages on nearly three years later. It's hard to imagine Putin didn't mull over his miscalculation when militant-led opposition forces seized Damascus and swept Syrian President Bashar al-Assad from power less than two weeks after launching an offensive.
The Kremlin's focus on the war against Ukraine is one of the factors that fed into the speed and success of the Syrian rebel offensive. Russian warplanes stepped up attacks on rebel-held territory as the offensive took hold, but with its military capabilities in Syria limited and its eyes on Ukraine, Moscow made no massive effort to stop it.
Now that Assad has fallen, what effect will Russia's big Middle East setback have on its war against Ukraine?
On the battlefield, not a huge one, analysts say, though it will depend in part on the fate of Russia's forces and bases in Syria: the airfield at Hmeimim and the naval facility at Tartus.
"A partial or full withdrawal would free up some reconnaissance, air force, special forces, and intelligence assets…. But Russia's presence in Syria is probably only a few thousand troops," Dara Massicot, a military analyst and senior fellow in the Russia and Eurasia Program at the Carnegie Endowment for International Peace, told RFE/RL in e-mailed comments.
Andriy Kovalenko, head of the Center for Countering Disinformation at Ukraine's National Security and Defense Council, said in a Telegram post that as of this past summer "there were about 6,000-7,000 Russian military personnel in Syria," including members of private military companies tied to the Russian state.
"Even if all these soldiers were transferred to the Russian Federation and then sent to the war against Ukraine, this would not significantly affect the situation on the front, given the rather high daily losses of the Russian Army in assault operations," Kovalenko wrote.
The Russian military has suffered massive casualties as it seeks to augment its gains in recent months, particularly in Ukraine's eastern Donbas region, ahead of what is widely expected to be an effort by U.S. President-elect Donald Trump to push for peace when he takes office in January.
Analysts pointed out that if Russian ships based at Tartus leave the Mediterranean, they cannot enter the Black Sea because Turkey has restricted passage through the Bosporus.
The departure of warplanes from Syria would be more meaningful because "it could strengthen the aviation group fighting against Ukraine," Kyiv-based military analyst Mykhaylo Samus told RFE/RL's Ukrainian Service. "It is the aviation component that could play a negative role" for Ukraine.
Ivan Kyrychevskiy, an analyst at the consulting firm Defense Express in Kyiv, was more dismissive, saying, "Russia's manipulation of its resources in Syria will in no way affect Ukraine" and that, at this point, "We can't say that the Russians are leaving [Syria,] and that's the end of it."
"Russia would be willing to offer a lot to the new coalition in Syria to retain some presence there as a first priority," Massicot told RFE/RL. "Russia will try to solidify agreements in Libya and Sudan as a partial offset."
Some experts said the reputational blow Russia has suffered in Syria may further sharpen Putin's hunger for control over Ukraine.
"Assad's collapse has…shaken Putin, making him less inclined to demonstrate flexibility with Ukraine," Tatyana Stanovaya, a senior fellow at the Carnegie Russia Eurasia Center, wrote on X. "The war in Ukraine has, to some extent, cost him Syria, which reinforces his unwillingness to compromise."
Ruth Deyermond, a senior lecturer in the Department of War Studies at King's College London, said the events in Syria seem unlikely to affect Russia's determination to prevail in Ukraine.
"Given how tightly Putin's presidency is tied to the war in Ukraine, how far he's been willing to reshape Russian economy and society, how many lives he's been willing to sacrifice for it, and how dependent he's made Russia on other states (China, Iran, North Korea), it's hard to imagine that the loss in Syria will make much difference because it's hard to see how the Kremlin could take victory in Ukraine more seriously than they already do," she wrote in e-mailed comments to RFE/RL.
Massicot suggested it would depend on how much of a presence in Syria and the surrounding region Russia manages to salvage.
"If Russia is pushed out entirely from Syria and they are unable to offset with basing elsewhere in the region, such a serious blow to Russian power would probably make Putin more rigid and determined to show control and 'success' in Ukraine," she wrote.
At the same time, Ukrainian commentators said the collapse of a regime that had stood as a symbol of newfound Russian clout abroad could prompt the rest of the world to view Moscow as weaker and more vulnerable than when Assad's grip on power seemed firm for almost a decade after Russia's military intervention in Syria in 2015.
The "myth that Russia is great, invincible, and so forth -- it's all just propaganda. And I think this was seen clearly once again in many capitals, and it will influence all subsequent events," Volodymyr Ohryzko, Ukraine's foreign minister in 2007-09 and now the head of a center for the study of Russia, told RFE/RL's Ukrainian Service.
"For us, I think this is a positive moment in our work with Western partners. And we must take advantage of this moment," Ohryzko said.
"We can use this in Ukraine, showing that nuclear powers can lose. The Soviet Union lost in Afghanistan, the United States essentially lost in Vietnam," Ukrainian political analyst Oleksandr Khara told RFE/RL's Ukrainian Service, adding it could help persuade Kyiv's supporters "that we can win in Ukraine if they help us with the necessary weapons and other things."
"We've seen in the past that the West has been willing to extend further support to Ukraine when they've had military successes against Russia. The Kremlin's inability to take any serious steps to prevent this geopolitical humiliation [in Syria] shows how overstretched they are in Ukraine," Deyermond wrote. "That and the failure of Putin's recent nuclear threats should encourage NATO members in their support for Ukraine."