The United States demanded Russia addresses the movements of Iran, Bashar al-Assad, and their allied militias, following an agreement to create “de-escalation zones” in Syria. However, Moscow, most probably, ignored US demands and, instead, prioritized commitment to the outcome of the agreement. 

This commitment was put to test for the first time during the battle for al-Tanf border area, where Russia did nothing but alerted Tehran and the militias, who continued to advance to the Iraqi-border avoiding only the US military al-Tanf air base. Moreover, Iran, once again, stepped up the challenge launching six missiles from its Kermanshah Province into Deir Ezzor City in eastern Syria in an unprecedented engagement that elicited no reaction from Russia. 

It is important to note that US-Russian relations, in context of developments in Syria, is an indicator of Moscow's position on Tehran's movements in the war torn country. In other words, When Russian- US mutual understanding is in place, Moscow works on setting the pace of Iran’s actions in Syria. However, at times of crisis, Moscow ignores Iran’s behavior, and would, at best, send a tacit or veiled message to its ally Tehran.

Moreover, friction between Russia and Iran comes within the context of Moscow’s attempts to maintain a critical balance between Iran and Turkey as its two contestant regional allies competing for influence in Syria.

However, it can be said that there are two stages in the Russia-Iran relations in Syria that are linked to geostrategic movements on the Syrian scene. That is to say, when the conflict was going on within the so-called “useful Syria”, the friction between Russia and Iran was at a higher level than in operations conducted west of the Euphrates River. Later, when the US expanded its military presence and launched preparations for the battle for Raqqa, the level of Russian-Iranian disagreement went down, adding ambiguity to Russia’s position on Iran’s project of a Shiite crescent  in the region as well as on Iran’s recent use of missiles in Syria. 

This has raised several issues within this context. For one, Russian pressures have often forced Iran to change the rules of the game. And while Iran’s ambitions in Syria have no ceiling, the consequences of these issues, in turn, raise questions over the future of the the relationship between Tehran and Moscow. 

Limited Rift

Collaboration between Russia and Iran in Syria has escalated recently, although limited cracks between them emerged. In one situation, for instance, a crisis broke out in August 2016 when Russia announced that its jet fighters will use Nojeh Air Base in Iran's western province of Hamadan to conduct military operations in Syria. Iran viewed its ally’s announcement as an act of embarrassment before its domestic public opinion. However, the crisis was gradually contained. 

Less than four months later, another crisis erupted while settlements were being worked out in Aleppo City, northern Syria. To the resentment of Tehran, Russia touted the settlement as a victory achieved by Bashar al-Assad regime and Moscow, while ignoring the Iranian role. However, overlooking this attitude could not prevent a recurrence. Tehran came under fire from the international community for the Iranian sectarian behavior that dominated a settlement involving the towns of Foua and Kefraya in Idlib, northern Syria. Both Russia and the international community put pressures on Iran. 

In March 2017, Russia’s Izvestia newspaper said that Iran agreed to withdraw its Shiite militias from some areas in Syria under oversight from Russia, which warned Iran not to deploy other militias to replace withdrawn ones. Iran heeded the warnings. 

Divergent positions between Russia and Iran, about the participation of the United States, resurfaced again in the run up to the Astana peace talks. While Russia was in favor of a role for Washington, Iran took a diametrically opponent position. 

However, in all these occasions, Russia succeeded in putting pressures on Iran. 

In the lead up to a military action in Raqqa by the US-led Global Coalition To Counter ISIS, at the beginning of the President Donald Trump's term, friction between the US and Iran escalated. Washington relied on Moscow to curb Tehran, and, following the understanding that was reached about four de-escalation zones in Syria,  Russian Foreign Minister Sergey Lavrov was asked to restrain Iranian movements. 

With the first Iranian movement towards these zones, US forces positioned at the al-Tanf air base near the Iraqi border with Syria bombarded a military convoy of pro-Iranian militias. The strike came after Moscow demanded the advance of these militias towards the US base be halted. Russia announced that its contacts with Iran in this regard were useless. 

In fact, Moscow has not tried to prevent the US strike, rather Russia overlooked it, according to some views. Moscow saw the strike as a punishment for Iran’s trespassing and unilateral moves. Russian media outlets reported that Russia coordinated with Iran and  al-Assad regime. 

It appears that Russia also opposes Iranian tactics coordinated with its People's Mobilization Forces (better known as the Hashd al-Shaabi) to reach the Iraqi border with Syria. However, Russia has not expressed its opposition and it is likely detaching itself from a mediation role in this situation or seeking to capitalize on the US-Iranian friction in Syria to serve its own interests at a later stage.

Complicated Scene 

Cases of Russian-Iranian polarization, from which Washington was not very much distant, show that Tehran responds only formally to warnings from Moscow. This does pose several issues, including that Russian pressure is also only formal, or tactical.

For instance, Moscow expressed its opposition to Iran’s advances towards the Iraqi border with Syria in the battle for al-Tanf area, but has not prevented these movements when the pro-Iranian militias changed their path only to advance towards the same target. This is a sign that Moscow’s view is, perhaps, that Tehran may move freely only away from the contact lines of the four de-escalation zones. This may be in line with statements from Syrian military officials, carried by Izvestia's defense commentator, Nikolay Surkov, that movements towards the Iraqi border is to prevent the US-backed Free Syrian Army battalions from reaching the highway connecting Palmyra to Deir Ezzor thus preventing the Syrian regime’s forces from breaking the siege laid on Deir Ezzor. 

It can possibly be said that if true, this view does not contradict plans developed by Russia and its allies for Raqqa. This may support the fact that the United States is currently building a new military base in the Zakf area where it plans to deploy defense systems as part of the Badia region in southern Syria. 

Moreover, Russia has not made any reaction to the Iran’s missile strike on Deir Ezzor while it was quick to condemn the United States’ recent shooting down of a Syrian regime’s Sukhoi Su-22 bomber, and even suspended the deconfliction channel and hotline with the United States. What can be concluded from this is that Moscow’s view is that the margin of disagreement with Iran can be used on a case by case basis within the framework of its relations with Washington. That is, in some cases Moscow acts as a mediator between Tehran and Washington, and in others capitalizes from the United State’s military targeting of Iran, and even seeks to exploit the two parties’ preoccupation with the conflict. 

In conclusion, it can be said that the margins of disagreement between Russia and Iran remain under control, no matter how wide they become. However, there are factors prompting certain levels of Russian reaction. These include Russia’s relations with other states, such as the United States and Turkey. Nonetheless, all developments have proved that no party to the conflict will sacrifice its alliance with other parties, and that the mechanism of dialogue is an effective tool in settling disagreements that can break out between any two parties. Hence, this mechanism is not likely to lose effectiveness in the short term but is also unlikely to prevent friction between parties within a certain margin that would not allow their convergence to break down.