Call of Duty 4: Modern Warfare introduces a variety of game play styles into the single player campaign completely new to the Call of Duty series. The game moves away from the standard three country-specific campaign style, and allows the plot to play through more like a film style plot with interlaced story lines from the perspective of the player as Paul Jackson, a member of the United States Marine Corps 1st Force Recon and Soap MacTavish, a member of the British 22nd SAS Regiment.
There is also a variety of cameo-style missions where you play as various other soldiers such as an AC-130 Spectre Gunship gunner, or as one part of a two man sniper team behind enemy lines in a flashback style mission. Even a mission in the Middle East as part of the USMC 1st Force Recon to rescue a bogged down tank.