• The downfall of Assad has threatened Russia's military presence in Syria along with its wider strategic objectives.
• Russia's bases in Syria made it a major diplomatic player in the Middle East.
• The bases were also crucial for its activities in Africa.

The fall of Bashar Assad has thrown Russia's military presence in Syria into question. It also poses a threat to Russia's ability to project power throughout the Middle East and beyond.

On Sunday, Syrian rebels, led by the Islamist group Hayat Tahrir Al-Sham, overthrew Syria's longtime autocratic ruler.

It followed a dizzying two-week campaign that caught the world off guard and many are now trying to work out what will come next for the country.

Russia has been a close ally of Syria and has leases on two military bases in the country, giving it a strategic foothold in the Middle East.

"It hits them hard," Edmund Fitton-Brown, a senior advisor to the Counter Extremism Project, said of Russia.

He added: "Syria has been their most reliable Arab ally."

A springboard to power

In 2017, Syria granted Russia a 49-year lease on the Hmeimim air base and the Tartus naval base, in return for military assistance.

Russia has used the bases to project power in the Mediterranean and into Africa, and as a counter to NATO's southern flank.

"These bases are the most important bases outside the direct sphere of Russian influence," Andreas Krieg, a Gulf specialist at the Institute of Middle Eastern Studies at King's College London, told Business Insider.

Ann Marie Dailey, a geopolitical strategist at RAND, told BI that despite its massive landmass, Russia "doesn't have great geography for power projection."

"It doesn't have warm water ports that have direct access to the oceans," she added. "And so having a port in the Mediterranean is incredibly strategically useful."

Hmeimim, meanwhile, gives Russia a refueling base and overflight access throughout the Middle East and on to Africa, she said.

On Sunday, Ukrainian military intelligence said that Russia had pulled two ships from Tartus, and had transferred weapons from Hmeimim.

BI was unable to independently verify the report.

But satellite images captured by Planet Labs PBC show Russian warships that had been seen in Tartus earlier this month were gone as of Monday.

Kremlin spokesperson Dmitry Peskov said Russia intended to have serious discussions with future Syrian authorities about access to the bases, but that it is too soon for now.

The potential loss of influence in Syria is not just about state power. The bases have also allowed support for the activities of the Russian paramilitary group Wagner.

"If you look at the Wagner footprint in Africa, you can tell that it's been enabled by the fact that they have that access in Syria to support those operations," said Dailey.

According to the Institute for the Study of War, losing the bases in Syria will "immediately" interrupt Wagner's rotation and resupply efforts.

Russia's ambitions for global leadership

Russia's involvement in Syria is a legacy of the Soviet era when the USSR traditionally maintained strong ties with other socialist states.

Russia propped up the Assad regime for more than a decade, notably sending aid during the 2011 Arab Spring, and troops and weapons to help counter the uprising in 2015.

Russian President Vladimir Putin had many reasons to stick his neck out for Assad.

"By backing Assad, Russia positioned itself as an indispensable player in regional politics, thereby increasing its diplomatic leverage," said Ali Bilgic, a professor in international relations and Middle East politics at the UK's Loughborough University.

But the huge cost of invading Ukraine appears to have forced Russia to choose between the two.

It "really speaks to how stretched thin Russian forces are," according to Dailey.

Putin has based Russia's international stature on the idea it can play a major role in different parts of the world, said Cristian Nitoiu, a Russia-focused lecturer in diplomacy and foreign affairs, also at Loughborough University.

Yet Putin's refusal to help Assad this time "basically shows that Russia was unable to support one of its long-lasting friends," Nitoiu said.

"The events in Syria can be seen as a sort of strategic failure on the part of Russia, and the optics look really bad," he added.

An uncertain future

In a statement on Sunday, Russia's foreign ministry said it was maintaining contact with "all" Syrian opposition groups, adding that while Russia's Syrian bases are on high alert, there's no serious threat to their security at the moment.

Russia has called Hayat Tahrir Al-Sham a terror group — so the fact that they are communicating with rebel groups now "demonstrates the importance of these bases," Dailey said.

HTS is also designated a terror group by the US and the UN.

What the US does regarding events in Syria will also be pivotal to what sort of foothold Russia can maintain, Loughborough University's Bilgic said.

On Saturday, President-elect Donald Trump posted on Truth Social: "THIS IS NOT OUR FIGHT. LET IT PLAY OUT. DO NOT GET INVOLVED!"

Should the US withdraw all involvement, Russia could exploit any ensuing power vacuum. But "this scenario appears improbable," Bilgic said.

In fact, diminishing Russian influence in Syria is a huge strategic draw for the US, he said, adding that there is also a concern that a new Russia-backed government could give room to ISIS, as well as threats to Israeli security.

Russia's presence in Syria has also helped it shape its objectives in energy markets, Bilgic said.

"Economically, the Tartus base played a role in Russia's energy strategy, helping to counter competing projects like the Qatar-Turkey pipeline," he said.

A grim reminder

What has happened in Syria in recent days may lead to some sleepless nights in Russia.

"I think it will rattle some folks in the Kremlin to see just how quickly Russia's military had to withdraw," Dailey said.

Assad's fall may also be a grim reminder for those in power in Russia of the necessity of crushing domestic resistance quickly, she said.

"Anyone in the Kremlin, because they've studied Russian history, knows that an autocratic regime can crumble very quickly."