Russia–Syria–Iran–Iraq coalition

The Russia–Syria–Iran–Iraq coalition (RSII coalition), also referred to as 4+1 (in which the "plus one" refers to Hezbollah of Lebanon), is a joint intelligence-sharing cooperation between opponents of the Islamic State of Iraq and the Levant (ISIL) with operation rooms in Syria's Damascus and Iraq's Green Zone in Baghdad. It was formed as a consequence of an agreement reached at the end of September 2015 between Russia, Iran, Iraq and Syria to "help and cooperate in collecting information about the terrorist Daesh group" (ISIL) with a view to combatting the advances of the group, according to the statement issued by the Iraqi Joint Operations Command. The statement also cited "the increasing concern from Russia about thousands of Russian terrorists committing criminal acts within ISIS."

In October 2015, it was suggested that the Russia–Syria–Iran–Iraq coalition may have been devised during the visit by Qasem Soleimani, commander of the Iranian Quds Force, to Moscow in July 2015. During the early days of the operation, the Russian Air Force were backed by the Syrian Armed Forces, Army of the Guardians of the Islamic Revolution, and allied militias. The United States, along with its NATO and Arab allies, have criticized this coalition; most airstrikes during the first week of the campaign, they say, struck areas held by rebel groups opposed to both the Syrian government and ISIL.

For two and a half decades, the Russian elite were split on Iran. Some, like Russian Prime Minister Dmitry Medvedev, saw Iran as a bargaining chip in possible deals with the Western world. On the other hand, Eurasianists like Aleksandr Dugin wanted a Russo-Iranian alliance to counter Western influence.

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