Special operations are military operations generally considered distinct from ordinary military operations, usually for one of two reasons: either they are conducted by specialized forces (e.g. 'special forces'); or they are operations that are part of a broader clandestine activity, for example, undertaken in support of other agencies such as the CIA. The first definition might be considered forces-based or oriented; the second, organization-based or oriented.
Conventional definitions of special operations vary. In Special Operations and Strategy: From World War II to the War on Terrorism by James D. Kiras, Kiras acknowledges the problem of defining special operations:
A primary reason why special operations have not been well understood historically is definitional in nature. Defining special operations appears to present few challenges, as one can start by describing the characteristics of "regular" operations and then compare the differences. Special operations can be viewed as a subset of regular operations or anything beyond conventional operations, as in "that class of military (or paramilitary) actions that fall outside the realm of conventional warfare during their respective time periods." Too broad a definition, however, opens the door for gross interpretation.
While Kiras concedes that under some definitions "almost all covert and clandestine direct action activities of intelligence agencies or other paramilitary forces also must be considered as special operations," and also that special operations may serve as means of achieving some foreign policy objective, Kiras still favors a strictly military definition, saying:
Although special operations have been called "self-contained acts of war," their primary military utility is to improve the military performance of conventional forces while achieving other strategic effects by targeting enemy vulnerabilities.
Kiras' definition is intra-military, viewing special operations as augmenting conventional operations. A similarly narrow definition is given by the Department of Defense Dictionary of Military and Associated Terms which defines special operations as:
Operations requiring unique modes of employment, tactical techniques, equipment and training often conducted in hostile, denied, or politically sensitive environments and characterized by one or more of the following: time sensitive, clandestine, low visibility, conducted with and/or through indigenous forces, requiring regional expertise, and/or a high degree of risk.
Prouty's definition of special operations
Col. L. Fletcher Prouty defined special operations in David T. Ratcliffe's Understanding Special Operations: Part III, Chpt. 1 as:
military services providing support to the clandestine activities of the government, usually clandestine activities that are at least nominally under the control of the CIA. There are official papers on this, and I as said earlier that we derive the authority from the NSC Directive No. 5412.
Prouty's definition emphasizes support inasmuch as the operations do not necessarily originate with the military services themselves. He also stresses the organizational structure that gives rise to special operations and the legal authority with which they are conducted. Rather than attempt to limit the definition of special operations to a strictly military point of view, Prouty's analysis situates special operations in the broader context of organization inside the Department of Defense and the United States federal government, as well as in the history of the period.
Special Operations and Clandestine Operations
Prouty also discusses special operations and how they differ from related terms in The Secret Team:
In pursuit of the business of definitions in this most elusive of professions, few terms have been so confused and misused as "special services". These two words simply mean clandestine operations. General Donovan's office was called Strategic Services, and his duties were described as special services. It was all the same clandestine operations. As the intelligence profession has labored through its first quarter-century since World War II, these terms have acquired additional synonyms. Clandestine operations are also known as covert operations, special operations, and peacetime operations or peacetime special operations, and secret operations.
There are two other terms that need clarification here in order that they not be confused with the above. Secret intelligence is the deep penetration of the enemy by secret agents and other devices. It is more specifically clandestine intelligence, as differentiated from the more open and more academic type of intelligence. This leads to intelligence operations, which may or may not be clandestine, but are operations carried out to obtain intelligence, and not operations carried out to achieve a certain objective as a result of the gaining of certain intelligence input data. In the former, the operation is carried out to get intelligence, and in the latter the operation is carried out using intelligence input data.Then there are secret intelligence operations, which are deeper and more clandestine operations carried out to get deep-secret intelligence data. It can be said that it is the business of secret intelligence operations to get information required in the making of foreign policy that is unavailable through routine and overt intelligence channels.
In general, Prouty seems to separate clandestine operations and special operations. The former are any operations that are clandestine or secret. This necessarily includes special operations, which must be kept secret in order to have any chance of success. But in ordinary use, the term clandestine operations refers to what generally falls under the purview of the intelligence services. Special operations, by contrast, though secret, are generally the province of the military.