[3][4] It was formed as a consequence of an agreement reached at the end of September 2015 between Russia, the Islamic Republic of Iran, Iraq and the Syrian Arab Republic to "help and cooperate in collecting information about the terrorist Daesh group" (ISIS) with a view to combatting the advances of the group, according to the statement issued by the Iraqi Joint Operations Command.

"[5] 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.

[12] The United States of America has been particularly hostile to the activities of Iran, Russia and Hezbollah in Syria since the start of the civil war, have criticized this coalition.

[11][17] Responding to an official request by Syrian government,[18] in September 2015, Russia sent its warplanes and other military hardware and combat troops to Bassel Al-Assad International Airport near Latakia to be ready for their operation.

[21] At the end of September 2015, a joint information center in Baghdad was set up by Iran, Iraq, Russia, and Syria to coordinate their operations against ISIL.

[citation needed] According to Russian foreign minister Sergey Lavrov's statement made in mid-October 2015, prior to the start of its operations in Syria, Russia invited the U.S. to join the Baghdad-based information center but received what he called an "unconstructive" response.

[26] In April 2014, Hossein Amir-Abdolahian, the Iranian deputy foreign minister, said: "We aren’t seeking to have Bashar Assad remain president for life.

"[27] On 24 July General Qasem Soleimani visited Moscow[8] to devise the details of the plan for coordinated military action in Syria.