Special mission units have been involved in high-profile military operations, such as the killing of Osama bin Laden and the attempted hostage rescue of Kayla Mueller.
[3] JP 3-05.1 defines a "special mission unit" as "a generic term to represent a group of operations and support personnel from designated organizations that is task-organized to perform highly classified activities".
In the early 1990s commander in chief of SOCOM, General Carl Stiner, identified both Delta Force and SEAL Team Six as permanently assigned special mission units in congressional testimony and public statements.
[6] In 1998, Under Secretary of Defense for Policy Walter B. Slocombe publicly referred to special mission units during a briefing to the Senate Armed Services Committee: "We have designated special mission units that are specifically manned, equipped and trained to deal with a wide variety of transnational threats" and "These units, assigned to or under the operational control of the U.S. Special Operations Command, are focused primarily on those special operations and supporting functions that combat terrorism and actively counter terrorist use of weapons of mass destruction.
These units are on alert every day of the year and have worked extensively with their interagency counterparts.