Global Thermonuclear War is a removed multiplayer gametype in Call of Duty: Modern Warfare 2and Call of Duty: Modern Warfare 3. Each side would fight to capture a Tactical Nuke in the middle of the map. Once a team has captured it, a countdown automatically starts, and lasts 40 seconds. When the countdown ends, the nuke explodes, killing all players on the map and winning the game for the team that captured the nuke. For a team to capture the nuke, players have to be in the area around the nuke. For every second in that area, a point is given to that player's team. Once 100 points have been scored by one team the countdown begins.
Global Thermonuclear War is only accessible through modding. A Hardcore variant also exists.