From the Call of Duty Wiki
"Sergeant" Kamarov was an Russian loyalist frequently tasked with helping SAS units operating in Russia. Given his close proximity to SAS units every time they got into trouble and support from his men to SAS units he was probably an important foot soldier in the Russian Loyalist Spetznaz with the rank of sergeant to cover his importance. He appears several times throughout Call of Duty 4: Modern Warfare and is a friend of Gaz and Captain Price and has worked with them several times, with the city of Beirut being mentioned in one mission. He makes them go on several side missions to assist loyalist Russian forces against the ultranationalists before escorting them to Nikolai, and this results in tension and anger from the SAS troops. . He later assists the SAS and Marines in a joint operation and the negative feelings from the SAS have worn off by then. Kamarov appears once more as he saves what remains of the SAS (Namely, Soap) from Zakhaev and his guards. Soap's vision whites out at the end in the same way Paul Jackson's did when he died. So it is possible that none of the team survive.
