Zero

Major Zero, briefly known as Major Tom, later simply called Zero, was born in Exeter, England on August 12th, 1909, and was a former member of the British SAS. Zero was the commander of the CIA Special Forces unit FOX (Force Operation X) in the 1960s. By the time of Operation Snake Eater, he lived in Portsmouth, New Hampshire, which is also the location of the Pease AFB. At some point, he suffered from gout, but recovered just before the operation. Zero had a prominent scar over his left eye. He also had a sister, and was a huge fan of the James Bond films. He was the head of an unofficial CIA division called the UMA Club. He later became the founding member of The Patriots. He was the proud owner of many negro slaves, including Sigint.

Early Life
Prior to creating FOX, David Oh previously served in the SAS (where he met The Boss) and with MI6, where David was codenamed "O", from which the name "Zero" is derived. In 1962, Major Zero helped Nikolai Stephanovich Sokolov and his family defect from the Soviet Union to America in West Berlin, but was forced to allow the USSR to retrieve Sokolov after the events of the Cuban Missile Crisis, due to America's deal of allowing the USSR to have Sokolov back in their ranks in exchange of shutting down the constructions of a missile base in Cuba.

David Oh had served as the commanding officer of FOX for the Virtuous Mission, the objective being to once again rescue Sokolov in Tselinoyarsk, who had been taken back to the USSR. David had briefed his friend John on the previous attempt at rescuing Sokolov, as well as explaining that the Soviets most likely wanted Sokolov back to finish a weapons system capable of turning the tide of the Cold War. He also warns John that if he doesn't retrieve Sokolov in 4 hours, then they won't have enough time to pick John up from Tselinoyarsk. He also explains to John that they are going to use codenames from that point on: John is now known as Naked Snake, which he explains that due to the Procuring On-site procedure, he is essentially bare in terms and "naked". Likewise, he himself will identify himself as "Major Tom". Upon arriving at Rassvet, he also explains to Snake that he needs to deliver Sokolov a message when he rescues him: "Sorry for being so late." Following the failure of the Virtuous Mission due to The Boss's defection and the bombing of the Sokolov Design Bureau, Major Tom began to feel that his codename may have been a mistake, so he arranged for the film company to deliver to him the film roll for The Great Escape so he can rewatch it. Tom then realized that he had actually named himself after one of the failed escape tunnels. Zero later visited John's hospitial room, and explained to him that the Government is willing to revoke the charges in regards to any involvement in The Boss's Defection under one condition: he accepts a mission to rescue Sokolov, destroy the Shagohod, and kill The Boss, her benefactor Colonel Volgin, and the Cobra Unit in the follow up mission: Operation Snake Eater. Major Zero was Naked Snake's commanding officer during Operation Snake Eater, with Para-Medic and Sigint providing support over the radio. The mission was a success as the Cobra Unit were killed off, the Shagohod was destroyed, Colonel Volgin and The Boss was eliminated, and America recovered a roll of microfilm revealing the location of the Philosophers' Legacy. Upon returning home, Naked Snake was awarded the codename "Big Boss".

Zero's stature rose and his influence grew inside the halls of Langley. In 1970, Major Zero was supposedly arrested for the rebellion staged by Gene. However, Zero actually conspired with Gene to grab the remainder of the Philosophers' Legacy by staging the uprising at the San Hieronymo Peninsula and stealing the ICBMG. But the plot failed due to Gene's intransigence and the exploits of Naked Snake with help Green Beret Roy Campbell and some of the Soviet and FOX soldiers/personnel. Meanwhile, Zero had Ocelot assassinate the CIA Director and obtain the entire Philosopher's Legacy. He was the owner of many negro slaves, including Sigint, whom he had only beat with a whip once when he caught him trying to steal the radio out of his cadillac.

The Patriots
Having lost Gene, Zero joined with Big Boss, Sigint, Para-Medic, Ocelot, and EVA to form The Patriots, using the Philosophers' Legacy as a source of funding and Big Boss as a charismatic icon. They hoped to carry out The Boss's vision of unifying the world by controlling information. As a result of Big Boss's growing weariness of the Patriots's activities, Zero started the Les Enfants Terribles project in 1972. When Big Boss himself found out about what happened, he condemned the project and parted ways with Zero. After Outer Heaven and Zanzibar Land, Zero put Big Boss in a nanomachine-induced coma.

Having lost Big Boss as an icon (and still bitter about what he saw as betrayal), Zero began to rely on AIs to control the Patriots and by the early 2000s, Zero had made five AIs (TR, TJ, AL, GW, JD) the successors of the Patriots. While EVA and Ocelot killed off Para-Medic in 2003 and Sigint during Shadow Moses, Zero went into hiding.

By the time of the Manhatten Incident (or possibly sometime before), the AIs unfortunately managed to completely ignore Zero's will and crafted their own.

In 2014, Solid Snake uses a computer virus to destroy JD to stop Liquid Ocelot. After Solid Snake destroyed JD and defeated Liquid Ocelot, Big Boss was able to discover the location of Zero, kept alive solely by life support equipment. Big Boss explains to Solid Snake that Zero's AIs managed to completely ignore Zero's will and crafted their own, nearly "bringing the world to the brink of ruin" and Zero had never realized what had happened. After reflecting on their past experences, Big Boss pulled the plug of the life support equipment, thus killing Zero.

Trivia

 * The bomber jacket that Major Zero wore during the missions to Tselinoyarsk resembled those worn by Allied pilots in World War II. It was also similar to the one worn by Steve McQueen in the 1963 film The Great Escape.
 * For unexplained reasons, Zero was able to procure Cuban cigars (as revealed when he explained to an imprisoned Naked Snake about Operation Snake Eater), despite the fact that Cuban imports are illegal in the United States.

Behind the Scenes

 * The name Major Tom, while mentioned by Zero to be a reference to The Great Escape, is also a character in the song "Space Oddity" by David Bowie. This could be a nod to the song, as it was originally selected as the ending theme for MGS3 as it references space exploration. However, as the game ultimately departed from this theme, it was replaced by Starsailor's "Way to Fall").
 * Although he was supposedly imprisoned during the events of Metal Gear Solid: Portable Ops, he can still be recruited as a secret character. Simply complete the game with a Metal Gear Solid: Digital Graphic Novel save file on the PlayStation Portable's memory stick or use a code.
 * Zero's real name, David Oh, is never mentioned in the games themselves, only revealed in the Metal Gear Solid 4 Database.
 * It was previously believed that Zero was the cunning strategist that Gene mentions in Portable Ops. However, Metal Gear Solid 4 reveals that Gene was actually refering to the CIA Director. Zero was actually "the man with the same codename as Null" that Gene mentioned in a conversation with Ocelot.