Nuclear briefcase

The Nuclear football, also known as the atomic football, the button, the black case, or just the football, is a briefcase acting as a mobile terminal to access nuclear launch centers and their payload of Nuclear missiles. It is primarily utilized by the President of the United States if he is away from nuclear command centers in the event of a nuclear attack, although similar devices exist.

Hot Coldman/Peace Sentinel
Hot Coldman and the Peace Sentinels utilized a similar device to the nuclear football during the 1974 Peace Walker Incident, for the mobile nuclear retaliation system Peace Walker. During the late stages of the incident, he had the briefcase handcuffed to his arm, although he was later forced by the KGB agent Vladimir Zadornov to input the code after the latter changed targets to Cuba. While travelling on a MSF chopper to Mother Base, Coldman, by that point dying from severe blood loss, accessed the briefcase and inputted the code (1976), thus sending the false data to Peace Walker, and by extension several third parties, including NORAD.

Arsenal Gear
By the time of the 2009 Big Shell Incident, the Football had undergone various improvements: Namely, it can be used to access Arsenal Gear's nuclear payload, and the President needs to input the code of his own free will (ie, he can't be drugged or coerced into using the code), as sensors are inside that detect whether the President was within his normal brainwaves or heart rate, and also utilizes the DNA base order and physiological data as further insurance that only the President can utilize the case. In addition, it also does a vitalization re-check from the President before it can truly confirm the order. President James Johnson, a disgruntled member of the Patriots, was convinced by Solidus Snake to do so for the first check, although he was kept alive to ensure the vitalization recheck was in order after he learned that Solidus had different aims from him. The code was terminated when Revolver Ocelot, acting on Patriot orders, killed James Johnson by shooting him.