United Kingdom/Modern Warfare

Counter-terrorism in Ukraine (1996)
The British Special Air Service attempted an assassination, the first one the British government had authorized since the Second World War, on the Russian Ultranationalist terrorist, Imran Zakhaev, in the Chernobyl Zone of Alienation in a flashback sequence in Call of Duty 4. The mission was not successful, but the two agents were extracted without casualties.

Second Russian Civil War (2011)
The British Special Air Service is involved with United States Marines and Russian Loyalists in covert operations against the Russian Ultranationalists and Middle Eastern OpFor in the Bering Strait, Russia, and Azerbaijan in the majority of the Call of Duty 4: Modern Warfare plot. They were successful in killing the leader of the Ultranationalists, Imran Zakhaev, but failed to stop their followers from taking over Russia.

World War III and chemical weapon attacks on the country (2016)
Numerous British operatives (e.g. Simon "Ghost" Riley) are seen as a part of Task Force 141, an elite paramilitary group dedicated to continuing their fight against the Ultranationalists. Also, Russia launched terrorist attacks in the U.K. as part of an invasion of Western Europe in Call of Duty: Modern Warfare 3.

Notable People from the UK

 * Captain John Price - SAS and Taskforce 141
 * Captain John "Soap" MacTavish - SAS and Taskforce 141 (KIA)
 * Lieutenant Simon "Ghost" Riley - SAS and Taskforce 141 (KIA)
 * Captain / Major General MacMillan - SAS / Baseplate
 * Gaz - SAS (KIA)
 * Sergeant Wallcroft - SAS
 * Corporal Griffen - SAS (KIA)
 * Sergeant Marcus Burns - SAS
 * Mac - SAS (KIA)
 * Sergeant Newcastle - SAS
 * Sergeant Arem - SAS
 * Corporal Barton - SAS
 * Archer - Taskforce 141 (MIA) or (KIA)