Intelligence agencies

An intelligence agency is a government agency responsible for the collection, analysis or exploitation of information and intelligence in support of law enforcement, national security, defense and foreign policy objectives. Means of information gathering are both overt and covert and may include espionage, communication interception, cryptanalysis, cooperation with other institutions, and evaluation of public sources. The assembly and propagation of this information is known as intelligence analysis or intelligence assessment.

Described below are examples of various intelligence agencies.

Defense Intelligence Agency
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.

Pacifica Ocean, an agent of Cipher, implied that Cipher managed to take control of the DIA by the time of the Peace Walker Incident in late 1974. 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 the assassination virus FOXDIE that was hitting walls until Naomi Hunter got involved in creating it. The DIA later allowed for FOXDIE to be injected into Snake during the Shadow Moses Incident.

Former members
 * Nastasha Romanenko
 * Richard Ames

Inter-Services Intelligence
The Inter-Services Intelligence (ISI) is the premier Intelligence service of the Islamic Republic of Pakistan, operationally responsible for providing critical national security and intelligence assessment to the Government of Pakistan. Critics of the ISI have long accused it of using designated terrorist groups and militants to conduct proxy wars against its neighbors. Rivalry between the ISI and the civilian government has also been alleged.

National Security Agency
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. Pacifica Ocean, an agent of Cipher, also implied that Cipher managed to take control of the NSA by the time of the Peace Walker Incident in late 1974.

On January 24, 2000, the NSA facility in Fort Meade 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

Secret Intelligence Service
The Secret Intelligence Service (SIS), 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

StB
In former Czechoslovakia, State Security or StB, 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

Behind the scenes
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. In the "Previous Operations" summary in Metal Gear Solid, the organization is instead named as the Czech International Secret Police.

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

According to a voice casting 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 is a member of the CIA. Because of this, it is unknown if the NSA reference is canon.''