Congressional oversight of the intelligence community (IC) enables Members to gain insight into and offer advice on programs and activities that can significantly affect or influence U.S. foreign policy. This In Brief responds to Congress's ongoing interest in oversight of covert action and clandestine activities in particular. The distinction between military and intelligence activities described as covert and clandestine can be confusing. What agencies are authorized to conduct covert action and clandestine activities? What are their legal authorities for doing so? Which military terms describe activities that might seem similar but are distinct from covert action? Prior to 1974, no statute existed that enabled Congress to conduct oversight of the intelligence community. Congress exercised what some have described as "benign neglect" of intelligence. In earlier instances, when it could have exercised greater oversight—such as over the CIA's orchestration of the 1953 coup in Iran—Congress trusted that the executive branch and intelligence community were acting in accordance with the law. Congress also did not question whether particular covert actions or other sensitive intelligence activities were viable as a means of supporting U.S. national security. In the 1970s, controversy over public disclosure of CIA's covert action programs in Southeast Asia and the agency's domestic surveillance of the antiwar movement spurred Congress to become more involved in intelligence oversight. In 1974, the Hughes-Ryan amendment of the Foreign Assistance Act of 1961 (§32 of P.L. 93-559 ) provided the first statutory basis for congressional oversight and notification to Congress of covert action operations. Investigations by two congressional committees—in the Senate, chaired by Idaho Senator Frank Church, and in the House, chaired by Representative Otis Pike—provided the first formal effort to understand the scope of intelligence activities. These committees became the model for a permanent oversight framework that could hold the intelligence community accountable for spending appropriated funds legally and supporting identifiable national security objectives. In 1975, Congress established the Senate Select Committee on Intelligence (SSCI) and the House Permanent Select Committee on Intelligence (HPSCI). Congress later refined its oversight of the intelligence community when the executive branch directed covert action operations without notifying Congress in advance. In August 1980, out of concern for maintaining operational security, President Carter chose not to inform Congress prior to the attempt to rescue American hostages held by the Iranian regime. In the mid-1980s, the Reagan Administration did not inform Congress about a covert initiative to divert funds raised from the sale of arms to Iran to support the Contras in Nicaragua. Through the Intelligence Authorization Acts (IAA) of 1981 ( P.L. 96-450 ) and 1991 ( P.L. 102-88 ), Congress revised procedures to try to ensure that the executive branch would, in the future, provide timely, comprehensive notification of all covert action and other "significant anticipated intelligence activity." The evolution of congressional oversight of intelligence, which emphasized the exclusive jurisdiction of the SSCI and HPSCI, vice the congressional defense committees, was, however, arguably out of alignment with the evolution of military operations and intelligence activities in the field. In the field, the military and intelligence communities increasingly integrated their activities for greater effect in the post-9/11 environment. A reportable intelligence activity, therefore, was often of interest to the congressional defense as well as intelligence committees. Yet, in Congress, the intelligence and defense committees have different notification standards and processes. The statutory authority for a particular intelligence or defense activity has determined the jurisdiction thereof: Title 50 of the U.S. Code provides the statutory authority for intelligence activities, regardless of which agency carries them out; Title 10 of the U.S. Code provides the statutory authority for military activities. Notification of Congress, therefore, has had the potential for artificially defining intelligence activities as separate and distinct from military activities. As a result, congressional committees may be unevenly informed about both kinds of activities, some of which may be indistinguishable regarding the respective risks they pose in terms of compromise, loss of life, and impact on U.S. national security. Covert action is codified as an activity or activities of the United Sates Government to influence political, economic, or military conditions abroad, where it is intended that the role of the United States will not be apparent or acknowledged publicly. It does not include activities with the primary purpose of acquiring intelligence, traditional counterintelligence activities, traditional activities to improve or maintain the operational security of United States government programs, or administrative activities; traditional diplomatic or military activities or routine support to such activities; traditional law enforcement activities conducted by United States government law enforcement agencies or routine support to such activities; activities to provide routine support of any other overt activities of other United States government agencies abroad. Covert action is generally intended to influence conditions short of an escalation by the United States that might lead to a sizable or extended military commitment. Unlike traditional intelligence collection, covert action is not passive. It has a visible, public impact intended to influence a change in the military, economic, or political environment abroad that might otherwise prove counterproductive if the role of the United States were made known. Covert action also requires a finding by the President, providing written notification to Congress that the impending activity supports "identifiable foreign policy objectives." Covert action cannot be directed at influencing the domestic environment: "No covert action may be conducted which is intended to influence United States political processes, public opinion, policies, or media." While covert action is historically most closely associated with the CIA, the President may authorize other "departments, agencies or entities of the United States Government," such as DOD, to conduct covert action. Offensive cyberspace operations—defined as operations "intended to project power by the application of force in and through cyberspace"—may also be called covert action if they are conducted under authority of Title 50 of the U.S. Code , Section 3093, which provides the statutory provisions for oversight for covert action. Historic examples of covert action include the CIA's orchestration of the 1953 coup in Iran; the 1961 Bay of Pigs invasion of Cuba; the Vietnam-era secret war in Laos; and support to both the Polish Solidarity labor union in the 1970s and 1980s and to the Mujahidin in Afghanistan during the 1980s. These and other examples highlight the mixed record of use of covert action, favorable, unfavorable, or undetermined and still unfolding through second- and third-order effects. The term clandestine activity is not defined by statute . DOD doctrine defines clandestine activities as "operations sponsored or conducted by governmental departments in such a way as to assure secrecy or concealment" that may include relatively "passive" intelligence collection information gathering operations. Unlike covert action, clandestine activities do not require a presidential finding but may require notification of Congress. This definition differentiates clandestine from covert , using clandestine to signify the tactical concealment of the activity. By comparison, covert activities can be characterized as the strategic concealment of the United States' sponsorship of activities that aim to effect change in the political, economic, military, or diplomatic behavior of an overseas target. Because clandestine activities necessarily involve extremely sensitive sources and methods of military operations or intelligence collection, their compromise through unauthorized disclosure can risk the lives of the personnel involved and gravely damage U.S. national security. Examples include intelligence recruitment of, or collection by, a foreign intelligence asset, and military sensitive site exploitation (SSE) of, or surveillance of, a facility in a denied or hostile area. SSE is one of many military operations that can be conducted clandestinely, without the acknowledgement—at least initially—of U.S. sponsorship. These examples of clandestine activities can be further categorized as traditional military activities or routine or other-than-routine support for traditional military activities, operational preparation of the environment (OPE ) , and sensitive military operations , all of which are discussed in more detail below. Clandestine activities can also include defensive or offensive operations in cyberspace, in which both the activity and U.S. sponsorship may be classified. Since 9/11, when military and intelligence activities became increasingly integrated, Congress has taken renewed interest in the two military exceptions to the statutory definition of covert action: traditional military activities and routin e support to traditional military activities. Though neither term is itself defined in statute, Congress's intent regarding traditional military activities and routine support to traditional military activities is relevant to understanding the range of military activities that have notification requirements that are less stringent than for covert action. These terms, which were first cited as exceptions to covert action in P.L. 102-88 , the Intelligence Authorization Act for FY 1991, may include activities that are difficult to distinguish from covert or clandestine intelligence activities. In a joint explanatory statement attached to the conference report for P.L. 102-88 , the conference committee provided an extended discussion of its intent as to the meaning of traditional military activities : It is the intent of the conferees that 'traditional military activities' include activities by military personnel under the direction and control of a United States military commander (whether or not the U.S. sponsorship of such activities is apparent or later to be acknowledged) preceding and related to hostilities which are either anticipated (meaning approval has been given by the National Command Authorities for the activities and or operational planning for hostilities) to involve U.S. military forces, or where such hostilities involving United States military forces are ongoing, and, where the fact of the U.S. role in the overall operation is apparent or to be acknowledged publicly. In this regard, the conferees intend to draw a line between activities that are and are not under the direction and control of the military commander. Activities that are not under the direction and control of a military command er should not be considered as " t raditional military activities [emphasis added]. In the Senate Select Committee on Intelligence (SSCI) report for the FY1991 Intelligence Authorization Act, the SSCI provided an expanded definition of its intent for the concept of routine support , which was considered to be: unilateral U.S. activities to provide or arrange for logistical or other support for U.S. military forces in the event of a military operation that is to be publicly acknowledged. Examples include caching communications equipment or weapons, the lease or purchase from unwitting sources of residential or commercial property to support an aspect of an operation, or obtaining currency or documentation for possible operational uses, if the operation as a whole is to be publicly acknowledged…. Other-than-routine support may be construed as a type of covert action since it includes a range of activities in which the U.S. role is unacknowledged and that may be intended to influence the environment of another country prior to commencement of the principal operation. [T]he [SSCI] would regard as 'other-than-routine' support activities undertaken in another country which involve other than unilateral activities. Examples of such [other-than-routine support] activity include clandestine attempts to recruit or train foreign nationals with access to a target country to support U.S. forces in the event of a military operation; clandestine effects to influence foreign nationals of the target country concerned to take certain actions to influence and effect [sic] public opinion in the country concerned where U.S. sponsorship of such efforts is concealed; and clandestine efforts to influence foreign officials in third countries to take certain actions without the knowledge or approval of their government in the event of a U.S. military operation. Operational Preparation of the Environment (OPE) is a DOD term for a category of traditional military activities conducted in anticipation of, in preparation for, and to facilitate follow-on military operations. It is a term DOD frequently uses, though its definition does not exist in statute. The DOD defines operational preparation of the environment (OPE) as the "conduct of activities in likely or potential areas of operations to prepare and shape the operational environment," with operational environment defined as a "composite of the conditions, circumstances, and influences that affect the employment of capabilities and bear on the decisions of the commander." Joint Publication 3-05, Special Operations , a doctrine issuance of the Joint Staff, describes preparation of the environment as an "umbrella term for operations and activities conducted by selectively trained special operations forces to develop an environment for potential future special operations," with "close-target reconnaissance … reception, staging, onward movement, and integration ... of forces ... [and] infrastructure development" cited as examples of such activities. Congress has expressed concern that the military overuses OPE to describe a range of military activities that can include, among other things, clandestine military intelligence collection that is neither subject to oversight by the congressional intelligence committees nor jurisdiction of the congressional defense committees. In the "Areas of Special Interest" segment of the House Permanent Select Committee on Intelligence (HPSCI) report ( H.Rept. 111-186 ) for its version of the Intelligence Authorization Act for FY2010 ( H.R. 2701 ), the committee indicated that it [noted] with concern the blurred distinction between the intelligence-gathering activities carried out by the [CIA] and the clandestine operations of the [DOD]…. In categorizing its clandestine activities, DOD frequently labels them as [OPE] to distinguish particular operations as traditional military activities and not as intelligence functions. The Committee observes, though, that overuse of this term has made the distinction all but meaningless. The determination as to whether an operation will be categorized as an intelligence activity is made on a case-by-case basis; there are no clear guidelines or principles for making consistent determinations. The Director of National Intelligence himself has acknowledged that there is no bright line between traditional intelligence missions carried out by the military and the operations of the CIA. Clandestine military intelligence-gathering operations, even those legitimately recognized as OPE, carry the same diplomatic and national security risks as traditional intelligence-gathering activities. While the purpose of many such operations is to gather intelligence, DOD has shown a propensity to apply the OPE label where the slightest nexus of a theoretical, distant military operation might one day exist. Consequently, these activities often escape the scrutiny of the intelligence committees, and the congressional defense committees cannot be expected to exercise oversight outside of their jurisdiction. In a section titled "Jurisdictional Statement on Defense Intelligence" under the "Committee Priorities" segment of its report ( H.Rept. 114-573 ) accompanying the Intelligence Authorization Act of 2017 ( H.R. 5077 ), the HPSCI reiterated that it is concerned that many intelligence and intelligence-related activities continue to be characterized as 'battlespace awareness,' 'situational awareness,' and – especially – [OPE].... The continued failure to subject OPE and other activities to Committee scrutiny precludes the Committee from fully executing its statutorily mandated oversight role on behalf of the House and the American people, including by specifically authorizing intelligence and intelligence-related activities as required by Section 504(e) of the National Security Act of 1947 (50 U.S.C. §3094(e)). Therefore, the Committee directs [DOD] to ensure that the Committee receives proper insight and access to information regarding all intelligence and intelligence-related activities of [DOD], including those presently funded outside the MIP. The Committee further encourages [DOD], in meeting this direction, to err on the side of inclusivity and not to withhold information based on arbitrary or overly technical distinctions such as funding source, characterization of the activities in question, or the fact that the activities in question may have a nexus to ongoing or anticipated military operations. Sensitive military operations are defined in statute as (1) lethal operations or capture operations conducted by the U.S. Armed Forces outside a declared theater of active armed conflict, or conducted by a foreign partner in coordination with the U.S. Armed Forces that target a specific individual or individuals, or (2) operations conducted by the armed forces outside a declared theater of active armed conflict in self-defense or in defense of foreign partners, including during a cooperative operation. This statutory definition allows Congress to provide oversight of the sort of military operations that have significant bearing on U.S. foreign and defense policy but are not clearly defined elsewhere in statutory oversight provisions. Sensitive military operations, which can be clandestine, have become an increasingly common feature of the post-9/11 counterterrorism (CT) landscape involving U.S. military intervention in countries such as Yemen, Pakistan, or Somalia that are outside areas of active hostilities (i.e., outside of Afghanistan, Syria, and Iraq). Examples of these operations include a lethal CT drone operation, or a military train , advise, and assist mission where U.S. forces supporting the security forces of a foreign partner nation may have to act in self-defense. It is easier to sort out how the intelligence and military activities defined in this report are categorized (and, consequently, determine how or whether Congress is notified) by first understanding their statutory authorities. The United States Code , which compiles and codifies laws of the United States, is organized into titles by subject matter. Title 10 of the U.S. Code provides much of the legal framework—sometimes referred to as authorities — for the roles, missions, and organization of DOD and the military services. Title 50, among other matters, provides much of the legal framework for many of the roles and responsibilities of the intelligence community, including the operations and functions of the CIA and the legal requirements and congressional notification procedures associated with covert action. References to Title 10 authorities and Title 50 authorities are sometimes used as colloquial shorthand by observers and experts to signify executive decision-making processes, congressional oversight structures, chains of command, legal authorizations to carry out certain types of activities, and legal constraints preventing certain types of activities that govern the respective operations and activities of DOD and the IC. Legal observers, however, have cautioned that such references reinforce a misperception that a clear distinction may be drawn between activities conducted under Title 10 authorities and activities conducted under Title 50 authorities. Some therefore assert that Title 10 and Title 50 authorities should instead be viewed as "mutually reinforcing" rather than "mutually exclusive" authorities. Others further emphasize that Title 10 is not the sole source of legal authorities for U.S. military operations, pointing to the President's authority under Article II of the Constitution as Commander in Chief of the U.S. Armed Forces, as well as laws enacted by Congress, such as the War Powers Resolution of 1973 ( P.L. 93-148 ; 50 U.S.C. §1541-1548) and the 2001 Authorization for Use of Military Force ( P.L. 107-40 ; 50 U.S.C. §1541 note). Some also cite the dual role of the Secretary of Defense under Title 10 and Title 50 to exercise authority, direction, and control over those elements of the IC that reside within the DOD organizational structure as support for the argument that Title 10 and Title 50 should be viewed as "mutually reinforcing." 

Summary: While not defined by statute, DOD doctrine describes clandestine activities as "operations sponsored or conducted by governmental departments in such a way as to assure secrecy or concealment" that may include relatively passive intelligence collection information gathering operations. Unlike covert action, clandestine activities do not require a presidential finding but may require notification of Congress. This definition differentiates clandestine from covert, using clandestine to signify the tactical concealment of the activity. By comparison, covert operations are "planned and executed as to conceal the identity of or permit plausible denial by the sponsor." Since the 1970s, Congress has established and continued to refine oversight procedures in reaction to instances where it had not been given prior notice of intelligence activities—particularly covert action—that had significant bearing on United States national security. Congress, for example, had no foreknowledge of the CIA's orchestration of the 1953 coup that overthrew Iran's only democratically elected government, or of the U-2 surveillance flights over the Soviet Union that ended with the Soviet shoot-down of Francis Gary Powers in 1960. Eventually, media disclosures of the CIA's domestic surveillance of the anti-Vietnam War movement and awareness of the agency's covert war in Laos resulted in Congress taking action. In 1974, Congress began its investigation into the scope of past intelligence community activities that provided the basis for statutory provisions for intelligence oversight going forward. The 1974 Hughes-Ryan Amendment to the Foreign Assistance Act of 1961 (§32 of P.L. 93-559) provided the earliest provisions for congressional oversight of covert action. In the late 1970s, Congress established a permanent oversight framework, standing up the House Permanent Select Committee on Intelligence (HPSCI) and the Senate Select Committee on Intelligence (SSCI). These committees were given exclusive oversight jurisdiction of the intelligence community. Recent events in North Korea, Yemen, and elsewhere have underscored the important function Congress can have in influencing the scope and direction of intelligence policy that supports United States national security. However, despite Congress's work during the past decades to establish statutory provisions for conducting intelligence oversight, those efforts have not always achieved Congress's desired result. For example, there has been occasional confusion over whether the congressional intelligence or defense committees have jurisdiction for oversight purposes. This confusion is due in part to overlapping or mutually supporting missions of the military and intelligence agencies, particularly in the post-9/11 counterterrorism environment. Intelligence and military activities fall under different statutory authorities, but they may have similar characteristics that warrant congressional notification (e.g., a need to conceal United States sponsorship and serious risk of exposure, compromise, and loss of life).