Base(s): The Helicarrier, Triskelion
S.H.I.E.L.D. is an espionage, law-enforcement, and counter-terrorism agency, it often deals with paranormal and superhuman threats.
The acronym originally stood for Supreme Headquarters, International Espionage, Law-Enforcement Division. It was changed in 1991 to Strategic Hazard Intervention Espionage Logistics Directorate (an alternative is Strategic Homeland Intervention, Enforcement and Logistics Division).
Usually led by Nick Fury as executive director (although he reports to a twelve-member council, whose identities even he does not know), this organization often operates as much as a covert agency as a quasi-military one, initially depicted as affiliated with the United States government. Later, S.H.I.E.L.D. was depicted as under the jurisdiction of the United Nations, with vast technological resources at its disposal, with U.N. General Assembly Resolutions and legislation passed in signatory nations aiding many of their operations. However, S.H.I.E.L.D. has been inconsistently portrayed as under U.S., rather than U.N., control - for instance, in Astonishing X-Men #3, Nick Fury explains S.H.I.E.L.D.'s inaction during an incident of genocide by stating that it did not occur on American soil.
S.H.I.E.L.D. started off as a top secret international organization (Fury was unaware of them when he was in the CIA) with a Supreme International Council made up of top officials and minds from across the world, including Tony Stark. Its first director was Rick Stoner, former head of the CIA, but he was quickly assassinated by Hydra, and the President of the United States recommended Nick Fury take the role. Later on, the ultimate authority of S.H.I.E.L.D. is revealed to be a cabal of 12 mysterious men and women who give Fury his orders and operational structure, leaving Fury to manage the actual implementation of these orders and stratagems.
One of S.H.I.E.L.D.'s unique technological innovations, the LMD (Life Model Decoy) — an extremely lifelike android used to replace people in imminent danger of being killed — was the basis for two major upheavals. First, the supervillain Scorpio stole the technology and used it to create the second team of villains called the Zodiac. Later, some LMDs known as the Deltites achieved sentience and infiltrated S.H.I.E.L.D. and Hydra both, replacing key members until Fury defeated them. This led to the disbanding of the original organization and its replacement by a new task force with the same acronym under the control of the U.N. ("Strategic Hazard Intervention, Espionage and Logistics Directorate") The new S.H.I.E.L.D. was meant to be more streamlined so Fury could personally oversee it, but would soon become a large organization again.
Organizational structure and procedure
Over the decades, various writers have depicted S.H.I.E.L.D.'s organizational structure in several different ways. The Official Handbook of the Marvel Universe (first edition) describes an eight-level ranking structure (technician, administrator, field agent, regional officer, special officer, regional director, special director, executive director), although providing almost no detail on other aspects of the Directorate's internal makeup. Years later, the miniseries Agents of Atlas mentioned a position of "sub director", and seemed to indicate that the administrative department of S.H.I.E.L.D. it itself referred to simply as "Directorate".
Most of S.H.I.E.L.D.'s agents are normal humans. At one point the organization attempted to set up a team of superhuman agents, composed of Marvel Man (the future Quasar), Texas Twister, Blue Streak and the Vamp but the latter two were secretly agents of the criminal organization The Corporation, and the team broke apart before it had its first official mission. A second team organized years later also lasted only a short while.
S.H.I.E.L.D. does employ some superhumans, including in its Psi-Division, composed of telepathic agents who deal with like menaces. S.H.I.E.L.D. also obtains help from independent heroes when their special abilities are needed. It has also accepted some superheroes and supervillains as members, but not in a separate unit.
Its headquarters is the Helicarrier, a massive flying aircraft carrier kept airborne at all times and, among other things, containing a squadron of jet fighters and housing an intercontinental ballistic missile (ICBM). In addition, S.H.I.E.L.D. maintains strong ties to the superhero community, especially Captain America, the Avengers, and the Fantastic Four, and often calls upon that community for aid on particular missions.
In the 2000s, depictions of S.H.I.E.L.D. imply a hierarchy of security clearance levels used either in place of, or alongside, the previously described rank structure. The security-clearance hierarchy operates on a scale ranging from "Level One", the lowest, to "Level Ten" as the highest security clearance anyone of any government can have.
Bases of operation
Although the various Helicarriers built over the years have long been considered S.H.I.E.L.D.'s primary mobile home base, the Directorate also maintains a number of land bases throughout the world, most notably "S.H.I.E.L.D. Central" in New York City. While some of these bases are publicly accessible on a limited basis, most are not publicly disclosed for reasons of planetary security. There are several fully equipped S.H.I.E.L.D. fall-out shelters scattered around the world, with twenty-eight of these being known only to Nick Fury. During the events of Civil War, Nick Fury was hiding in an American-based shelter. He also divulged the location of one to Captain America, so the Resistance to the Superhuman Registration Act could use it as a safe house.
The following organizations are related to S.H.I.E.L.D.:
A.R.M.O.R. (Altered-Reality Monitoring and Operational Response) is a sister agency to S.H.I.E.L.D. that monitors alternate reality incursions. In the comics it is stated that A.R.M.O.R. is so secret that it 'makes S.W.O.R.D. look like S.H.I.E.L.D., and S.H.I.E.L.D. look like the Post Office'.
S.T.A.K.E. is a S.H.I.E.L.D. subsidiary that specializes in dealing with supernatural occurrences.
S.W.O.R.D. (Sentient World Observation and Response Department), works with S.H.I.E.L.D. but specializes in extraterrestrial threats. Both organizations has been ambiguous on whether S.W.O.R.D. is a branch of S.H.I.E.L.D. or a sister agency.
A similar group as S.W.O.R.D., likewise affiliated with the U.N., is Starcore, which has worked with S.H.I.E.L.D. on several projects of joint interest, including establishing and maintaining a crewed facility on Earth's Moon.
W.A.N.D. stands for Wizardry, Alchemy and Necromancy Department, and is a division of S.H.I.E.L.D that specializes in matters relating to magic.