Miscellaneous groups

Counter Assault Team
The Counter Assault Team (CAT) is a unit within the Secret Service of the United States Government.

Former members
 * Hi-Tech Soldiers

DARPA
The Defense Advanced Research Projects Agency (DARPA) is an agency of the United States Department of Defense responsible for the development of new technology for use by the military. DARPA has been responsible for funding the development of many technologies which have had a major impact on the world, including computer networking (ARPANET), as well as NLS, which was both the first hypertext system, and an important precursor to the contemporary ubiquitous graphical user interface.

It was originally established in 1958 under the name of Advanced Research Projects Agency (ARPA), but it was renamed DARPA (for Defense) on March 23, 1972, then back to ARPA on February 22, 1993, and then back to DARPA again on March 11, 1996.

In 1970, ARPA became involved in several projects, including global positioning satellites, unmanned aerial vehicles, a human cannon, and an aircraft comparable to a UFO. ARPA also conducted a project called "Metabolism Dominance" that related to making soldiers fight without eating for five whole days, and another unnamed project that involved getting soldiers to fight without sleeping.

After the disasterous results of the Lady Mercury mission, Strangelove transferred from NASA to ARPA and fully dedicated herself to researching AIs in an attempt to avoid repeating the same tragedy, as it was the only place she could make a living from her AI research. Strangelove was later downsized from ARPA, which shortly thereafter became DARPA, as a result of the Detente era being ushered in.

During the 2000s, DARPA was involved in the creation of Metal Gear REX by ArmsTech after its Chief, Donald Anderson (formerly known as Sigint), himself a big supporter of nuclear deterrence theory, was heavily bribed by ArmsTech president Kenneth Baker to allow development. In addition, DARPA was also involved in the creation of the exoskeleton that was later utilized by Solidus Snake during the 2009 Big Shell Incident and the perfected Land Warrior System equipment that was later utilized by the Hi-Tech Soldiers.

Former members
 * Donald Anderson
 * Strangelove

Delta Force
The United States Army's "1st Special Forces Operational Detachment-Delta (1st SFOD-D)" — commonly known as Delta Force by civilians — is an integral element of the Joint Special Operations Command (JSOC). Delta Force's primary tasks are counter-terrorism and national intervention operations, although it is an extremely versatile group that is capable of assuming many mission types, including (but not limited to) hostage rescue, enemy raids, and covert enemy force neutralizations. Delta Force conducts missions similar to those attributed to the British Special Air Service (SAS), from which it was originally modeled.

Former members
 * Roy Campbell

DIA
The Defense Intelligence Agency, or DIA, is a major producer and manager of military intelligence for the United States Department of Defense, employing over 16,500 military and civilian employees worldwide. The Defense Intelligence Community is headed by the DIA, through its Director (who chairs the Military Intelligence Board), and coordinates the activities of the Army, Navy, Marine Corps, and Air Force intelligence components. The DIA and DIC provide military intelligence to warfighters, defense policymakers and force planners within the Department of Defense and the United States Intelligence Community, in support of U.S. military planning and operations and weapon systems acquisition. DIA, designated in 1986 as a Defense Department combat support agency, was established in 1961 as a result of a decision by Secretary of Defense Robert S. McNamara, under President John F. Kennedy. The Department of Defense created DIA with the publication of Directive 5105.21, "Defense Intelligence Agency" on August 1, effective October 1, 1961. The DIA was preceded by the Counter Intelligence Corps.

Nastasha Romanenko briefly worked for the DIA, which was where she met and eventually married Richard Ames before they ended up divorcing. At some point before the Shadow Moses Incident, the DIA was working on an assassination virus that was hitting walls until Naomi Hunter got involved in creating it. The DIA later allowed for the virus, codenamed FOXDIE, to be injected into Snake during the Shadow Moses Incident.

In the non-canonical Snake Tales story "Confidential Legacy", Roy Campbell and his brother Matt were both DIA agents.

Former members
 * Nastasha Romanenko
 * Richard Ames

DREBIN
DREBIN is a gun laundering network and Patriots proxy that functioned during the war economy. There were at least 893 members working for the group. After the Patriots were shut down, they became their own business.

Egg Plant
Egg Plant was the name of an extremist terrorist group, originally commanded by the Outer Heaven mercenary, Dirty Duck.

Former members
 * Dirty Duck

Extraterrestrial Environment Special Forces
The Extraterrestrial Environment Special Forces, also known as Black Ninja, was a special forces unit secretly formed by NASA, which envisioned future conflicts in outer space. The members of the group were technologically advanced ninja-like soldiers, outfitted with experimental flex armor and reflex-enhancing drugs (in what may have been a predecessor to the Cyborg Ninja project). However, the unit was disbanded before it saw action, due to its controversial nature, and was regarded as being too dangerous to exist. Afterwards, some of the members fled to Zanzibar Land, where they participated in the country's war of independence. One of these members was the former leader of the Outer Heaven Resistance, Kyle Schneider, who was experimented upon after narrowly surviving the NATO bombing of Outer Heaven.

Former members
 * Kyle Schneider

FARC
The Revolutionary Armed Forces of Colombia, commonly referred to as FARC (Fuerzas Armadas Revolucionarias de Colombia), is a rebel group that operates in Colombia. It's been active since 1964, financing its operations by forcing poor farmers to grow cocaine, which FARC operatives then sell abroad. It was the organization that was responsible for giving the Red Army the San Hieronymo Peninsula to use as their Missile Base in exchange for weapons and additional forces to fight the Colombian regime at the time, after the Red Army had failed in establishing a missile base in Cuba.

FBI
The Federal Bureau of Investigation (FBI) is the primary unit in the United States Department of Justice, serving as both a federal criminal investigative body and a domestic intelligence agency. The FBI has investigative jurisdiction over violations of more than 200 categories of federal crime. Its motto is "Fidelity, Bravery, Integrity," corresponding to the "FBI" initialism.

Hal Emmerich, while a college student, was recruited into the FBI under the ERF (Engineering Research Facility). However, at some point later, he was kicked out after he was caught monitoring and hacking the FBI's central database.

Psycho Mantis had a brief stint with the organization working as a Psychic Investigator. He would enter the minds of suspected killers and uncover the truth about their crimes. This eventually drove him psychotic and he later quit the Bureau and eventually joined FOXHOUND.

Naomi Hunter made up a false story about how her Japanese grandfather became assistant secretary to J. Edgar Hoover in the FBI and went undercover to help bring down the Mafia in New York, during the 1950s. Master Miller (who was really Liquid Snake) later revealed this was false as J. Edgar Hoover was a well known racist which meant there were only white FBI agents in his time as Director (1924-1972), and the Mafia undercover operations first started in Chicago in 1960, not New York.

The FBI agent who exposed President Nixon's involvement in the Watergate Scandal used the alias "Deepthroat."

While Master Miller (Liquid Snake in disguise) was trying to convey his suspicions about Naomi Hunter by pointing out various flaws in her backstory, he claimed that he used to work for the FBI. As Solid Snake stated that he was unaware of this, this may have been a lie crafted by Liquid Snake.

Former members
 * Psycho Mantis
 * Hal Emmerich

Force XXI
The United States Army's Task Force XXI program (TF-XXI for short), aka the Next-Generation Integrated Infantry Fighting System, was actually a series of trial exercises and initiatives that utilized virtual reality training for selected soldiers during the late 1990s by the United States Army in the interest of modernization, but it is said to have been under research and development by the U.S. Army since the 1980s. The goal was to test unique concepts, tactics, and technologies on the modern-day battlefield.

Some of the technology that was tested includes software-defined radios (which inspired the Codec designed by Mei Ling), digital transmitters installed on all their weapons, appliqué computers carried by each soldier (to minimize casualties and maximize combat effectiveness by sharing data), ground surveillance radar (which inspired the Soliton Radar System), satellite radio e-mail systems, and Unmanned Aerial Vehicles like the Cypher. TF-XXI participated in various advanced combat exercises during these trials. Jack (Raiden) took part in these trials exclusively during his solo special forces soldier training. Members of Force XXI also were given intel on military projects, such as the Land Warrior System.

In the early 2000s, selected subjects of the Force XXI trials were jointly assigned with former Outer Heaven and Zanzibar Land mercenaries (with the U.S. government paying their contracts) to create the Next-Generation Special Forces, which later participated in the Shadow Moses Incident.

Whether or not Jack took part in any gene therapy is unknown, though he was not a member of the Genome Army during the Shadow Moses Incident. It is possible that his participation in the Force XXI trials ended before the merger with the former mercenary forces.

Former members
 * Raiden
 * Various members of the Genome Army

FSLN
The Sandinista National Liberation Front (FSLN) is a socialist political party originating in Nicaragua. It was founded in 1961. Costa Rica had a boathouse that was originally owned by the FSLN before the Peace Sentinels invaded Costa Rica and held the Commandante hostage. They were backed by the KGB as part of its plan to instigate rebellions in the American continent, but their plan backfired when Amanda's FSLN unit turned on them. They often did drug trafficking in order to acquire the funds necessary for food, weapons, and troops, to their shame. During the Peace Walker Incident, the FSLN unit led by Amanda was in hiding from both the Nicaraguan national guard and the Peace Sentinels, the latter of whom often tortured and killed members of the FSLN unit who were unfortunate enough to be captured by them (the latter action was usually done after the FSLN members ended up breaking from the torture and stating the location of their compas.) The FSLN's nickname was the "watermelon sellers", which, contrary to what Big Boss thought (and what Kazuhira Miller told him), does not derive from smuggling weapons in hollowed out watermelons, but was derived from the fact that General Sandino's nickname sounded similar to the Spanish word for watermelon, "sandía"

Former members
 * Libre
 * Amanda Valenciano Libre
 * Chico

Green Berets
The United States Army Special Forces, aka the Green Berets, is a renowned Special Forces group that was originally formed in 1952 by Colonel Aaron Bank, based on the Jedburgh teams of the Office of Strategic Services. It is operated under the command of the United States Army. The Green Berets are tasked with five primary missions: unconventional warfare, foreign internal defense, special reconnaissance, direct action, and counter-terrorism.

A young soldier by the name of John served as a Green Beret until he joined the CIA, as the first field operative of FOX. He also met another member, Roy Campbell, while imprisoned during the San Hieronymo Takeover. During his mercenary work after leaving America, John, now christened as Big Boss, had briefly rejoined the Green Berets to participate in Vietnam. At some point after McDonell Benedict Miller (aka, Kazuhira Miller) left the Militaires Sans Frontieres, he briefly worked with the Green Berets. During the Gulf War, one of the Les Enfants Terribles clones, David, participated in the Green Berets and was part of a dispatch unit to infiltrate Western Iraq.

Former members
 * Big Boss
 * Roy Campbell
 * McDonell Benedict Miller
 * Solid Snake

GSG 9
The GSG 9 der Bundespolizei, formerly the German abbreviation of Grenzschutzgruppe 9 (translated as "Border Guards, Group 9") is the counter-terrorism unit of the German federal police. Founded after the Black September Olympic Hostage Crisis, it is considered to be among the best of such units in the world. In fact, many later counter-terrorism units of other nations were modeled after the GSG 9.

Former members
 * Fire Trooper
 * At least one member of the Four Horsemen

''According to the MSX2 manual for Metal Gear, Big Boss had previously served with GSG 9. However, this information was disregarded from his biography in the sequel's manual, and received no mention in the Metal Gear Solid 4 Database, so it is presumably no longer canon.''

Japan Self-Defense Forces
The Japan Self-Defense Forces (JSDF) were the unified military force of Japan. Founded in 1954, it was met with controversy due to Article 9 forbidding war from ever being enacted in Japan. However, Tokyo's official stance is that Article 9 of the Japanese constitution did not forbid self-defense, which allowed it to create a force for the purpose of self-defense. Kazuhira Miller was a former member for the Self Defense Forces, but quit due to not improving in the SDF, Yukio Mishima's suicide, and the fact that his mother died, so he no longer had a reason to continue.

Members
 * Kazuhira/McDonell Benedict Miller

Les Enfants Terribles
Les Enfants Terribles was a French terrorist group, once sub-commanded by Zanzibar Land mercenary, Running Man. The name of the group was presumably inspired by the the novel and 1950s film of the same name. It should not be confused with the 1970s government project of the same name.

Members
 * Running Man

NASA
The National Air Space Administration, also known as NASA, is an agency of the Executive Branch of the United States Government, responsible for the nation's civilian Space Program, aeronautics, and aerodynamic research. It was first founded in July 29th 1958, although it did not become operational until October 1st of the same year, as part of the Space Race. During the first years of its creation, it recruited a british woman studying AIs at the California Institute of Technology, Dr. Strangelove, into its Mercury Project, where she first encountered The Boss, as well as overseeing the experimental launch on April 21st of 1961 that resulted in The Boss's hospitalization.

On 1969, NASA also conducted its first landing on the moon with the Saturn V. However, a Soviet Spy within NASA stole blueprints relating to the Saturn V, which resulted in the modifications to the Silo at San Hieronymo Peninsula. During the Detente era of the 1970s, NASA's budget ended up slashed.

After the Outer Heaven Uprising, NASA captured Kyle Schneider and used him and other soldiers as a guinea pig for the Black Ninja project, with the goal of creating a unit called the Extraterrestrial Environment Special Forces unit for any conflicts in Outer Space. However, NASA was forced to shut down the project after controversy arose about the immorality of the project, which also resulted in the would-be members of the unit joining Zanzibar Land.

Former members
 * Huey Emmerich
 * Strangelove

NATO
The North Atlantic Treaty Organization is an intergovernmental military alliance formed by North American and European countries. It was established after World War II to counteract the threat posed by the Soviet Union and other Communist states, with the signing of the North Atlantic Treaty in 1949. The original member states were the United States, Canada, the United Kingdom, France, the Netherlands, Belgium, Luxembourg, Iceland, Norway, Denmark, Italy, and Portugal. Following the end of the Cold War, the former Eastern Bloc countries of Bulgaria, Estonia, Latvia, Lithuania, Romania, Slovakia, and Slovenia joined the alliance. NATO's role is to ensure the security of its member countries by political and military means, operating as a peacekeeping organization in various conflicts.

In 1995, NATO forces launched a massive aerial bombardment against Outer Heaven, shortly after the conclusion of Operation Intrude N313, to ensure the destruction of any remaining nuclear weapons. However, many war orphans and refugees were killed in the bombing, regardless of their ties to the regime or not, though the multinational forces deemed this as an acceptable loss as they were considered a liability. The truth was hidden from the media, and very few people ever learned of what really happened.

In the Metal Gear 2: Solid Snake'' manual, it was stated that FOXHOUND was a NATO unit formed in the 1990s. However, this has been retconned since Metal Gear Solid where FOXHOUND was instead labelled as a US Army Special Forces unit.''

NEST
The Nuclear Emergency Support Team, formerly known as the Nuclear Emergency Search Team, was a team of scientists, technicians, and engineers operating under the United States Department of Energy's National Nuclear Security Administration.

NEST was formed after an incident in late 1974 where President Gerald Ford was warned that an extortionist contacted the FBI and demanded $200,000 as he placed a nuclear bomb in Boston. Some mishaps occured, including the team of experts from the United States Atomic Energy Commission arrived with their radiation detection equipment arriving at a different airport, and Federal agents renting a fleet of vans carrying the equipment but forgetting to install it. The event later turned out to be a hoax, but it dawned on the government that they needed to create a team to search out nuclear threats to the homeland.

Nastasha Romanenko joined NEST around 1996 as a military and nuclear analyst. Fatman was briefly a member of NEST, but his mad behavior resulted in him losing his job at the organization.

Former members
 * Various members of the Genome Army
 * Nastasha Romanenko
 * Fatman

NORAD
The North American Aerospace Defense Command is a joint organization of the United States and Canadian militaries that provides aerospace warning, air soverignty, and defense for the two countries. Its headquarters is within the Cheyenne Mountain Air Force Base at Colorado, and was formed in 1958, although NORAD's directorate headquarters was built in 1961.

In 1974, the CIA Station Chief of Central America and leader of the Peace Sentinels: Hot Coldman, while conducting the Peace Walker project in Central America, arranged for Peace Walker's AI to leak false data to third parties should it ever enter nuclear launch mode. Coldman planned for this to occur on November 23rd 1974 due to the U.S. President and most of his cabinet leaving for Vladivostok to discuss the SALT II treaty, knowing full well that the military itself would be forced to consider nuclear retaliation with most of the White House cabinet absent. After being fatally wounded by Vladimir Zadornov, when the latter betrayed him and changed the target to Cuba, he activated Peace Walker, knowing that he would die before he could be forced to reveal the abort code. The data then was leaked to NORAD, and then taken over to the Pentagon, causing them to panic and think it was a real Soviet attack. Even after Peace Walker was rendered incapable of launching a nuclear strike, the data was still transmitted to NORAD.

NSA
The National Security Agency is a cryptologic intelligence agency of the United States government, administered as part of the United States Department of Defense. It is responsible for the collection and analysis of foreign communications and foreign signals intelligence, which involves cryptanalysis. It is also responsible for protecting U.S. government communications and information systems from similar agencies elsewhere, which involves cryptography. NSA's work is limited to communications intelligence; it does not perform field or human intelligence activities.

In September 1960, two NSA codebreakers, ADAM and EVA, defected to the Soviet Union. ADAM was the triple-spy better known as Ocelot. During Operation Snake Eater, a woman posed as EVA to aid Naked Snake in his mission while secretly plotting to steal the Philosophers' Legacy for the Chinese Government.

On January 24th 2000, the NSA facility in Fort Meade |suffered a total system shutdown for a 72-hour period. It was believed that a small group within the government had arranged the incident with the assistance of a notorious group of hackers, of which Emma Emmerich was a key member. This resulted in a full review of NSA's safety measures, which led to the decision to shift the data-gathering operations to an isolated location that would be safe from physical attack as well as cyber-terrorism. In 2005, Emma herself was recruited by the NSA after the government leaked the details of the Shadow Moses Incident to her.

Former members
 * ADAM (Ocelot)
 * EVA (NSA codebreaker)
 * Emma Emmerich
 * Nastasha Romanenko

''According to a leaked voice acting sheet for Metal Gear Solid 3: Snake Eater, Sigint was a member of the NSA during Operation Snake Eater. However, in the game, Major Zero tells Naked Snake that Sigint was actually a member of the CIA. Because of this, it is unknown if the NSA reference is canon.''

Octopus Cult
The Octopus Cult was a militant cultist group stationed in Scandinavia. They harbored a deep hatred of a Scandinavian village known as the Devil's Village for unspecified reasons. At some point, the Octopus cult attacked the Devil's Village and killed a majority of the villagers. They spared only one person, a little girl they referred to as "the Devil's child," only to force her to torture and murder her friends and family while laughing. This resulted in the girl, the one who will eventually become Laughing Octopus, gaining mental scars on the traumatic incident.

Outer Heaven Resistance
The Outer Heaven Resistance was a resistance movement based in South Africa, in the region occupied by the emerging mercenary state of Outer Heaven. The Resistance was led by Kyle Schneider, after his family were killed during undisclosed circumstances. Also, many members of the resistance were imprisoned.

Presumably made up of former locals and refugees opposed to the new military regime, they assisted Solid Snake in his mission to eliminate the threat of Outer Heaven to the rest of the world. However, after Snake's success, many members were killed during the subsequent NATO bombing of the area. Afterwards, the surviving members presumably allied themselves with Big Boss willingly in order to repay him for saving them, given Kyle Schneider's comments to Solid Snake.

Former members
 * Kyle Schneider (leader)
 * Diane
 * Jennifer
 * Steve

Rex Command
Rex Command was a reconnaissance command unit within the South African Special Forces Brigade. Jungle Evil, the Zanzibar Land mercenary, was a former member of this unit.

Former members


 * Jungle Evil

SIS
The Secret Intelligence Service, often referred to by its former name MI6, is responsible for supplying the British Government with foreign intelligence, operating under the formal direction of the Joint Intelligence Committee (JIC). It was formed in 1909, and its founder was Mansfield George Smith Cumming, although his codename was the first letter of his last name, "C." In his honor, members of the SIS had codenames derived from the first letter of their last names. Its existence was not officially acknowledged in public until 1994.

Prior to the formation of the FOX Unit in 1964, Zero was a member of MI6, under the codename "O" (derived from his real name of David Oh). In the early 1990s, Liquid Snake worked as an undercover SIS agent, during the Persian Gulf War.

Former members
 * O (Zero)
 * Liquid Snake

Small Boy Unit
The Small Boy Unit was a military unit which enlisted many child soldiers (possibly war orphans), and was commanded by a teenage Solidus Snake. The unit took part in the Liberian Civil War, and was where a young boy named Jack (Raiden) had his first taste of battle. In order to keep child soldiers controlled, they would be fed food mixed with gunpowder and toluene, and be forced to watch Hollywood action movies to help keep them focused on killing. They also played war games with real bullets. The children in the unit were apparently also forced to join, given Raiden's comments that "it was either kill or be killed." Little else is known about the unit. When the Patriots explain their plans to Raiden, they also stated that they chose Raiden out of all of the child soldiers because the other child soldiers faced up to their past and make amends every day, hinting that the surviving members of the unit were arrested or going through relief counseling.

Former members
 * Solidus Snake (unit commander)
 * Jack (Raiden)

Spezialeinsatzkommando
The Spezialeinsatzkommando, also referred to as SEK and previously known as Sondereinsatzkommando, was the special response team of the German State Police forces. Comparable to the GSG-9, they often are deployed in areas with riots and high crime rates in Germany's states. Although they are officially deployed in the Capital cities of their states, they can also have multiple units stationed in areas other than the capital city if these areas have a high enough crime rate. SEK was involved in trying to stop some terrorist attacks caused by the Les Enfants Terribles terrorist organization, and were the ones who gave the sub-commander of the terrorist organization the name Running Man.

StB
In former Czechoslovakia, the StB, known as State Security in English, was a plainclothes secret police force founded on June 30, 1945. Serving as an intelligence and counter-intelligence agency, any activity that could possibly be considered anti-communist fell under the purview of StB.

Former members
 * Gustava Heffner

In Metal Gear 2: Solid Snake, the StB still existed as of 1999, however, its real-life equivalent was dissolved on February 10, 1990, a few months prior to the game's release.

Tokugawa Heavy Industries
Tokugawa Heavy Industries is a company that created the exoskeletons worn by the Cyborg Ninjas. Both Gray Fox's and Raiden's helmets bear the company's name.

''Tokugawa Heavy Industries was originally featured in Policenauts, one of Hideo Kojima's early games. It is a reference to his early years as a designer and it is unknown whether the Tokugawa Heavy Industries in the Metal Gear series is the same company existing within the Policenauts and Snatcher universes. The name "Tokugawa" also appears on piping in Metal Gear Solid 2: Sons of Liberty, in the first floor pump room of the Big Shell's Strut A, and on boxes and machines in Strut E's parcel room. The Grand Game Plan also indicated that Emma Emmerich would also have been an employee of Tokugawa Heavy Industries.''

UMA Club
Unidentified Mysterious Animal Club or UMA Club, is an unofficial division of the CIA dedicated to cryptozoology, a fringe science focused on the search for animals which are considered to be legendary or otherwise nonexistent. It was founded and led by Major Zero. Sigint was also a member of the group, acting as its vice president. One of their biggest interests was the search for the Tsuchinoko, a plump snake-like creature cryptid. The club also expressed interest in finding a Megatherium or the De Loys' Ape in Colombia.

Former members
 * Major Zero (president)
 * Sigint (vice president)

''In Metal Gear Solid: Portable Ops, Sigint discusses Colombia's UMAs in an optional radio conversation if he is recruited as a playable character. He asks Snake and some members of his resistance to procure one while they are in the country. Big Boss also briefly references the UMA Club when speaking to Amanda about Chico's fascination towards UMAs, in Metal Gear Solid: Peace Walker. ''

United Nations
The United Nations (UN) is an international organization with 193 member states that was founded in 1945 after World War II to replace the League of Nations to stop war and have a platform of discussion. Its stated aims are facilitating cooperation in international law, international security, economic development, social progress, human rights, and achieving world peace.

The various member states voted circa 2009/2010 to create the war economy and utilize PMCs to deal with various conflicts because they were angered at America for its incident in 2009. America didn't agree to it, but was left with no other choice but to allow them to do so because America exported far too much military power during the Cold War and thus could not let its army get involved without suffering severe public backlash similar to that of the 2009 Manhattan Incident.

After the war economy collapsed due to the Patriots and its SOP system being taken offline due to FOXALIVE, Drebin speculated that with various countries going bankrupt due to their use of PMCs, and being under a debt severe enough that not even passing PMC restriction laws was going to be able to end the debt anytime soon, the UN will have a more important role than ever. However, he also implied that the UN, due to its history being no different than the Patriots in terms of control over people, will most likely end up creating a spiritual successor to the Patriots in terms of oppressive control and thus force the cycle to continue.

U.S. Air Force
The United States Air Force (USAF) is the aerial warfare, space warfare, and cyberwarfare branch of the U.S. armed forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on 18 September 1947 under the National Security Act of 1947. It is the most recent branch of the U.S. military to be formed.

During the Shadow Moses Incident a pair of F-16 fighters were sent to the island as a diversion, to aid Solid Snake's infiltration. However, they were shot down by the terrorist leader, Liquid Snake, piloting a Hind D. Towards the end of the incident, the island was to be bombed by F117 Nighthawks and B-2 bombers, but were called off at the last minute.

U.S. Navy
The United States Navy (USN) is the sea branch of the U.S. Armed Forces and one of the American uniformed services. It is a blue water navy with the ability to project force onto the littoral regions of the world, engage in forward areas during peacetime, and rapidly respond to regional crises, making it an active player in American foreign and defense policy. There were five fleets active in the United States Navy (six counting the Naval Reserve), which are the Second, Third, Fifth, Sixth, and Seventh fleets, which were stationed around the Atlantic coast of South America and West Coast of Central America alongside the portion of the Atlantic Ocean from the United States cost to the middle of the Atlantic, portions of the eastern and northern Pacific ocean (including the Bering Sea, Aleutian Chain, Alaska, and the Arctic), the areas around the Persian gulf/Red Sea/Arabian Sea and East Africa up to Kenya, Europe, and portions of Asia that included Korea and Japan, respectively.

The U.S. Navy, with the backing of the Patriots, conceived the Arsenal Gear program. This makes the backing of the RAY program by the Marine Corps confusing as the Navy is the parent organisation of the Marines. A Navy captain was killed, during the Big Shell Incident, by Dead Cell in order to retrieve "The Football" that was handcuffed to him. Also, SEAL Team 10 would have used Navy helicopters to board the Big Shell.

Richard Nixon served in the Navy against the Japanese in World War II until 1947, when he left to after a discharge in 1946.

Former members
 * Richard Nixon

UDT
Underwater Demolition Teams (UDT) were an elite special-purpose force established by the U.S. Navy during World War II. Their primary function was to reconnoiter and destroy enemy defensive obstacles on beaches where U.S. and Allied forces were going to make amphibious landings. They also served during the Korean War and the Vietnam War.

The UDTs pioneered combat swimming, closed-circuit diving, underwater demolitions, and midget submarine (dry and wet submersible) operations. They were the precursor to the present-day United States Navy SEALs.

In 1983, the UDTs were re-designated "Swimmer Delivery Vehicle Teams" (SDVTs). SDVTs have since been re-designated SEAL Delivery Vehicle Teams.

Former members
 * At least one member of the Four Horsemen

The Whispers
The Whispers were a legendary guerilla squad in North Vietnam. It was rumored that they were more advanced in jungle warfare than even the Green Berets. The Zanzibar Land mercenary Night Fright was the last surviving member of this unit.

Former members
 * Night Fright

Wild Geese
The Wild Geese were a mercenary group involved in an unknown number of African conflicts sometime during the 1970s and possibly the '80s. Big Boss fought with this unit at some point during his mercenary career.

Former members
 * Big Boss