In the Ukraine, Captain John "Soap" Mac tavish, Sergeant Gary "Roach" Sanderson, Captain John Price, Lieutenant Simon "Ghost" Riley are members of the elite British S.A.S and are on a mission to disable a small terrorist unit in a small abandoned Ukrainian town while being covered by US Army Delta Force Soldiers Master Sergeant "Sandman" and Staff Sergeant Derek "Frost" Westbrook. While on mission, the team takes out an abandoned school and does a breach and clear on a room containing three Russian terrorists and gaining inteligance on Vladimir Makarov, a former Red Army Colonel and K.G.B Lieutenant Commander, commander of Russian Special Forces and Navy and Terrorist Leader. The unit is forced to escape with cover of an AC-130 with Sandman and Frost's help. While running to a Sea Knight, the AC-130 was shot down and this resulted in Soap being hit with an RPG rocket. While Ghost and Roach were getting Soap, Price was covering them and was shot in the arm and had to change to his P.226 Pistol. While the unit was leaving, Price demanded that they leave him and as a result he was captured.

Years later, U.S Army Ranger Lieutenant General Shepard has betrayed Soap and Price, who was rescued from prison. Soon a fight began between Price and Shepard in which Shepard was winning until Soap throws a knife into Shepard's eye, which resulted in a war between the two and the entire US Army.