What’s at stake for Russia in Syria

Tartus Port is the second largest port city in Syria.
Google Maps
Tartus Port is the second largest port city in Syria.

The gridlock at the UN Security Council between the U.S.and Russia is dragging on, due to a gamut of competing interests in Syria.

(Read more: Syria strike would send 'global message': Menendez)

The Russia-Syria axis is rooted in a strong political and economic relationship that has been cultivated since the late 1950s. The bond has a deep cultural element: many Syrians go to Russia to study, while Russians go to Syria as holidaymakers, advisors or investors. Over the years, Russia has also played an essential role in restructuring the Syrian economy, and wrote off roughly 70 percent of Syria's $13.4 billion debt in 2005.

While reliable numbers are hard to come by, The Moscow Times estimated Russian investments in Syria at $19.4 billion in 2009, covering infrastructure, energy and tourism. But with outstanding projects ranging from a nuclear power plant to oil and gas exploration, the number today may be considerably higher.

(Read more: UK parliament votes against military action in Syria)

"The $20 billion figure is notional and should be treated with some caution," Richard Connolly, lecturer in political economy at the University of Birmingham, told CNBC.

Either way, Russia's trade with Syria is fairly insubstantial. According to Daniel Treisman, professor of political science at the University of California, Los Angeles, Russian exports to Syria amounted to$1.93 billion in 2011, or only 0.4 percent of Russia's total exports. That's less than its trade with Tunisia and Estonia.

Still, what stands out is that Russia-Syria trade is concentrated in the defense and energy industries. "The vast majority of Russian exports to Syria are armaments, which makes Syria relatively more important as an export destination for the Russian defense industry," Connolly said.

(Read more: U.S. Facing Test on Data to Back Action on Syria)

Data from the Stockholm International Peace Research Instituteindicated that between 2005 and 2010, Syria accounted for just over 1 percent of Russia's arms exports. Between 2011-12, analysts told CNBC, that number increased to four percent.

Russia's interest in Syria is of course geo-strategic as well as economic. It predominately hinges on the Mediterranean port of Tartus,which is often used to save the Russian navy the long voyage across the Black Sea. In September 2008, work started on converting the facility to a full naval base.

"Of course Russia would like to preserve its naval base in Tartus, but it will have to adjust to the outcome of the civil war, whatever that is," Treisman said.

Connelly said that although Tartus may not be significant militarily, it represents a last vestige of Russian influence in the region.

(Read more: UN weapons inspectors pull out of Syria early)

"It is... of symbolic importance. It marks Syria as one of the few countries in the region with which Russia continues to enjoy warm relations," he said.

The U.S. meanwhile has effectively withdrawn from Syria,leaving the bilateral relationship in shambles. In a research note late on Monday, the International Crisis Group suggested diplomatic efforts might prove more successful. It advised developing a "realistic compromise political offer" and reaching out to both Russia and Iran, "rather than investing in a prolonged conflicted that has a seemingly bottomless capacity to escalate."

For now, a Russian retreat from its anti-interventionist stance on Syria appears as unlikely as one by its U.S. counterpart, further clouding prospects for any political resolution.

(Watch: UN visits possible site of chemical attack in Syria)

"My view is that Russia can, and will, support Assad for as long as Assad can stake a claim to being the ruler of Syria, and as long as the diplomatic price remains relatively low," Connolley said.

Follow us on Twitter: @CNBCWorld