Zero

Major Zero, briefly known as Major Tom, later simply called Zero, was born David Oh 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 founder of The Patriots.

Early Life and Career
Prior to creating FOX, David Oh previously served in the SAS (it's here where David met The Boss) and with MI6, where David was codenamed "O", from which his codename "Zero" is derived. In 1962, David 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. At some point later, David also recruited Donald Anderson (in spite of his personal reluctance to do so, given Anderson's African American heritage) and Dr. Clark into the CIA as he recognized their potential. However, David ended up receiving complaints three days per month from personnel, relating to Anderson.

In 1964, David Oh had served as FOX's commanding officer 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 (a.k.a. Jack) 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 warned Jack that if he didn't retrieve Sokolov in four hours, then they wouldn't have enough time to pick Jack up from Tselinoyarsk. He also explained to Jack that they were going to use codenames from that point on: Jack was given the codename Naked Snake. David explained that due to the procuring onsite procedure, he was essentially bare in terms and "naked" while David likewise identifed himself as "Major Tom." Upon arriving at Rassvet, Major Tom also explained to Snake that he needed to deliver Sokolov a message when he rescued 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 felt that his codename might have been a mistake, so he arranged for the film company to deliver to him the film roll for The Great Escape so he could rewatch it. Tom then realized that he had actually named himself after one of the failed escape tunnels. David later visited Snake in his hospitial room, and explained to him that the Government was willing to revoke the charges in regards to any and all involvement in The Boss's defection under one condition: he had to accept the follow up mission Operation Snake Eater. David went under the codename "Major Zero" (based from his first codename "O") and was Naked Snake's commanding officer during Operation Snake Eater, with Para-Medic (Dr. Clark) and Sigint (Donald Anderson) providing support over the radio and EVA assisting Naked Snake with transportation. The mission was a success as the Cobra Unit were killed off, the Shagohod was destroyed, Colonel Volgin and The Boss were eliminated, and the American Philosophers recovered a roll of microfilm revealing the location of the Philosophers' Legacy. Upon returning home, Naked Snake was awarded the Big Boss codename by President Lyndon B. Johnson. As Snake left the White House, he ran into Major Zero but neither of the two say anything to each other. Not long afterward, Snake left FOX and America and drifted around nations as a mercenary while Major Zero left FOX. After he left FOX, Major Zero's stature rose and his influence grew inside the halls of Langley.

In 1970, Major Zero was supposedly arrested for treason. In actuality, Zero conspired with Ocelot to grab the remainder of the Philosophers' Legacy. Tired of the American Philosophers's bickering, Zero and Ocelot decided it was time to "end them" and then "reform" the Philosophers by staging Gene's rebellion on the San Hieronymo Peninsula and the stealing of a nuclear missile so the DCI to come out of hiding. However, they were unaware that Gene was serious in launching the nucelar missile towards the American Philosophers, thus framing the Russian Philosophers (interestingly, Ocelot never knew his conspirator was Zero while Gene had an idea as he referred to Zero as "the man with the same codename as Null"). However, Naked Snake and Roy Campbell were able to convince the Red Army soldiers and some of the FOX personnel to defect and help them against FOX and foiled Gene's plot. Meanwhile, Major Zero had supplied trajectory data in regards to where the missile was to be launched to the DCI. Zero then had Ocelot assassinate the DCI in order to obtain the entire Philosophers' Legacy and the list with the identities of the Philospher members. After Snake and Campbell returned to America, Zero shared with Ocelot the battle data of the Perfect Soldier Project and gave hints about "genomes" as bargaining chips. Ocelot argeed to stay working together under the condition that they recruit Big Boss (Naked Snake) in their new organization: The Patriots.

The Patriots
After Gene's rebellion, 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 had finalized Les Enfants Terribles, a project that illegally cloned Big Boss (with President Richard Nixon and the U.S. Army General as witnesses) in 1972. When Big Boss himself found out about what happened, he condemned the project, parted ways with Zero, left the United States, and formed his own private mercenary army.

Operation Peace Walker
Main Article

In 1974, Zero and the Patriots (referring to themselves as Cipher) orchestrated Coldman's Peace Walker project and AIs. Meanwhile, Zero recruited Pacifica Ocean (an orphaned woman under the alias of Paz Ortega Andrade) and Vladimir Alexandrovich Zadornov (a KGB agent under the alias of Professor Ramón Gálvez Mena), as well as contacting Kazuhira Miller in a business proposal (he agreed to help under the condition that the Militaires Sans Frontieres expanded) to get Big Boss to participate in their project without his knowledge.

Zero also ordered Pacifica to modify Metal Gear Zeke when the time came, and then hijack it and offer Big Boss the chance to rejoin them (the true purpose of the project), and should he refuse, frame the Militaires Sans Frontieres for being an extremist cult by launching a nuclear warhead from Metal Gear Zeke at the East Coast of the United States. Kaz later alerted them that she made edits to it, although he was left unaware of her framing MSF if Big Boss refused. Ultimately, this plot failed when Big Boss damaged Metal Gear Zeke and stopped Paz from launching a nuke, and Kaz presumably quit Cypher after what they did. However, Zero and the Patriots planned on using the twin sons (Solid Snake and Liquid Snake) as "insurance" in case they failed to both bring Big Boss back to their group and frame the Militaires Sans Frontieres.

Later Years
Years later, Big Boss plotted coup d'état (Outer Heaven and Zanzibar Land) against Zero. But after Solid Snake defeated Big Boss both times, Zero put Big Boss in a nanomachine-induced coma.

Having lost Big Boss as an icon (and possibly 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 created five AIs (TR, TJ, AL, GW, and JD) as his successors of the Patriots. While EVA and Ocelot had Dr. Clark killed by Gray Fox in 2003 and Donald Anderson personally killed off by Ocelot during the Shadow Moses Incident, Zero went into hiding.

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

In 2014, after Solid Snake used a computer virus to destroy the Patriots' AIs and defeated Liquid Ocelot, Big Boss was able to discover the location of Zero, kept alive solely by life support equipment. Big Boss explained to Solid Snake that the AIs (Zero's successors) managed to completely ignore Zero's will and crafted their own, nearly "bringing the world to the brink of ruin" with Zero never realizing what had happened and how the world "begin with zero." 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 injured Naked Snake about Operation Snake Eater), despite the fact that Cuban imports are illegal in the United States.
 * According to Sigint, Zero believed that he was once abducted by aliens.

Behind the Scenes

 * The name Major Tom, while mentioned by Major 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 Metal Gear Solid 3 as it references space exploration. However, as the game ultimately departed from this theme, it was replaced by Starsailor's "Way to Fall."
 * Although Zero was 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 Japanese voice actor (Banjo Ginga) in Metal Gear Solid 3 and Metal Gear Solid: Portable Ops also voiced Liquid Snake in Metal Gear Solid and Metal Gear Solid 2 and Liquid Ocelot in Metal Gear Solid 4.
 * 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 "deviously cunning strategist" that Gene mentions in Metal Gear Solid: Portable Ops. However, EVA reveals to Solid Snake in Metal Gear Solid 4 that Zero was actually "the man with the same codename as Null" that Gene mentioned in a conversation with Ocelot in Metal Gear Solid: Portable Ops and Coldman reveals that he is the man in question to Naked Snake (Big Boss) in Metal Gear Solid: Peace Walker.