A standoff between Russian soldiers and Iran-backed militias in the northern Syrian city of Aleppo could point to an end to the unlikely marriage of convenience between Moscow and Tehran in the war-wracked country.

The fighting in Aleppo killed at least 11 people, including civilians, a toll that could inflame tensions between the two sides that are generally believed to be working in concert in Syria.

Details surrounding the violence remain unclear. The Syrian Observatory for Human Rights said fighting may have been triggered over competing for control of city checkpoints, which brings in a lot of money for forces on the ground.

The standoff could also have stemmed from recent Israeli air strikes near Aleppo, which some Iran-backed militias say Russia has been involved in, through coordination with Tel Aviv.

In any case, the Iran-Russia tensions are but the latest misstep in a long, rocky military partnership that is likely to be further strained in the future.

Last year, the two countries fell out after Iran-backed militias blocked the evacuation of Aleppo, prompting Russia to launch air strikes in the towns of Kafraya and Foua to pressure Tehran to agree to a deal.

The year before, Hezbollah fighters, in coordination with Iran, prevented Russian soldiers from entering Wadi Barada to monitor militias’ suspected violations of a ceasefire there.

The incidents show that Russia and Iran, while nominally on the same side in the Syrian conflict, do not always act in concert. While both are committed to the general aim of keeping the regime of Syrian President Bashar Assad in power, they are looking to advance their own influence and riches as the war winds down.

Other factors likely contributed to the recent shift, including Iran-backed militias’ switch to guerrilla tactics as a direct outcome of Iran’s declining financial assistance.

This brings us to the United States’ withdrawal from the Iran nuclear deal, officially known as the Joint Comprehensive Plan of Action, and its reimposition of sanctions in 2018. Just after the US move against Tehran at that time, a flurry of diplomatic activity between Washington and Moscow was recorded, leading to speculation that Russia could abandon its situational ally, Iran, in return for better relations with the United States.

However, it has become clear that Russia was not ready to burn all its bridges with Tehran, an ally with an entrenched presence in Syria and with which Moscow has collaborated on a wide variety of issues, including energy and security in the Caspian region and the Afghan conflict.

By keeping Iran in its orbit, Moscow saved a valuable bargaining chip that it could use in negotiations with Washington and its allies in the Middle East.

Such a strategy has proven effective. Wary of Iran’s involvement in the region, some Arab countries moved closer to Russia, hoping to convince Moscow to change its course of action in Syria and elsewhere. Of course, those attempts failed, producing a new reality: Arabs keeping Moscow close but not ready to take the bait again.

Now, as Russia remains stuck in poor bargaining, Iran is exploiting the free rein it has gained in Syria to expand its influence — by creating local Shia militias, indoctrinating Syrians and spreading Khomeini-style fundamentalism.

Tehran is also gaining influence economically. A 2018 report by Chatham House indicated that Tehran had attempted to expand its presence on the ground through land grabs, including a large area entering downtown Damascus.

The report pointed to Iran’s exporting of goods to Syria and the signing of at least five cooperation deals that would allow Tehran to “invest in a port in the coastal city of Tartus, use 5,000 hectares of agricultural lands, explore phosphate mines south of Palmyra and license mobile phone operators.”

Russia, however, with one of the most powerful intelligence services in the world, has tried to keep Iran’s manoeuvres in check, with sources in Damascus suggesting Moscow has blocked some of Iran’s economic expansion plans.

But for how long will Russia be able to keep Iran in check and for how long does Moscow expect other players in the region to tolerate its dance with the wolves?

Such questions could soon be answered but, for now, what is clear is that Russia preserving Iran as a bargaining chip is an old, ineffective ruse.

The clock is ticking and it won’t be long before Tehran creates a militia force in Syria that functions like Hezbollah in Lebanon and the Popular Mobilisation Forces in Iraq.

Of course, the Russians, who in the 1980s drank from the poisoned chalice of the Afghan guerrilla warfare, know better than anyone how disastrous the end will be if Iran’s militias aren’t kept in check.

And, while Russians may look like the main winners today, they face many challenges in Syria, including a ticking clock, domestic pressure, reconstruction challenges, regional and international disapproval and potential backlash from radical Shia militias that will always view Russians as intruders and infidels.

As we see more and more standoffs in Syria, a Pandora’s box could indeed open for Russia and never be shut again. Only the future will tell if Moscow will act before it is too late.