Clandestine operation in the context of "Espionage"

The Directorate of Operations (DO), less formally called the Clandestine Service, is a component of the US Central Intelligence Agency. It was known as the Directorate of Plans from 1951 to 1973; as the Directorate of Operations from 1973 to 2004; and as the National Clandestine Service (NCS) from 2004 to 2015.

The DO "serves as the clandestine arm of the Central Intelligence Agency (CIA) and the national authority for the coordination, de-confliction, and evaluation of clandestine operations across the Intelligence Community of the United States".

The Special Activities Center (SAC) is the center of the United States Central Intelligence Agency (CIA) responsible for covert operations. The unit was named Special Activities Division (SAD) prior to a 2015 reorganization. Within SAC there are at least two separate groups: SAC/SOG (Special Operations Group) for tactical paramilitary operations and SAC/PAG (Political Action Group) for covert political action.

The Special Operations Group is responsible for operations that include clandestine or covert operations with which the US government does not want to be overtly associated. As such, unit members, called Paramilitary Operations Officers and Specialized Skills Officers, do not typically wear uniforms.

The Bay of Pigs Invasion (Spanish: Invasión de la Bahía de los Cochinos, sometimes called Invasión de Playa Girón or Batalla de Playa Girón after the Playa Girón) was a failed military landing operation on the southwestern coast of Cuba in April 1961 by the United States and the Cuban Democratic Revolutionary Front (DRF), consisting of Cuban exiles who opposed Fidel Castro's Cuban Revolution, clandestinely and directly financed by the U.S. government. The operation took place at the height of the Cold War, and its failure influenced relations between Cuba, the United States, and the Soviet Union.

By early 1960, President Eisenhower had begun contemplating ways to remove Castro. In accordance with this goal, Eisenhower eventually approved Richard Bissell's plan which included training the paramilitary force that would later be used in the Bay of Pigs Invasion. Alongside covert operations, the U.S. also began its embargo of the island. This led Castro to reach out to the U.S.'s Cold War rival, the Soviet Union, after which the U.S. severed diplomatic relations.

The term "need to know" (alternatively spelled need-to-know), when used by governments and other organizations (particularly those related to military or intelligence), describes the restriction of data which is considered very confidential and sensitive. Under need-to-know restrictions, even if one has all the necessary official approvals (such as a security clearance) to access certain information, one would not be given access to such information, or read into a clandestine operation, unless one has a specific need to know; that is, access to the information must be necessary for one to conduct one's official duties. This term also includes anyone with whom the people with the knowledge deem necessary to share it.

As with most security mechanisms, the aim is to make it difficult for unauthorized access to occur, without inconveniencing legitimate access. Need-to-know also aims to discourage "browsing" of sensitive material by limiting access to the smallest possible number of people.

The Special Operations Forces of the Armed Forces of the Russian Federation, commonly known as the Special Operations Forces (abbr. SOF; Russian: Силы специальных операций; ССО, romanized: Sily spetsial’nykh operatsiy; SSO), are strategic-level special forces under the Special Operations Forces Command (Russian: Командование сил специальных операций, KCCO, romanized: Komandovaniye sil spetsial'nykh operatsiy, abbr. KSSO or KSO) of the General Staff of the Armed Forces of the Russian Federation. They are also a structural branch and an independent unit of the Armed Forces.

The first units of what would become the Special Operations Forces were transferred from the General Staff Directorate (GRU) in 2009 as part of the continuing 2008 Russian military reform. The Special Operations Forces Command, established in 2012, was announced in March 2013 by the Chief of the General Staff Valery Gerasimov. According to Gerasimov, Russian authorities designed the SOF as a strategic-level asset: élite special-operations-force units of the KSSO whose primary missions would be foreign interventions including counter-proliferation, foreign internal defense operations and undertaking the most complex special operations and clandestine missions for protecting the interests of the Russian Federation.

Land and Liberty (Russian: Земля и воля, romanized: Zemlya i volya or Zemlia i volia; also sometimes translated Land and Freedom) was a Russian clandestine revolutionary organization in the period 1861–1864, and was re-established as a political party in the period 1876–1879. It was a central organ of the Narodnik movement.