Special Mission Unit

The term Special Mission Unit or Special Missions Unit (SMU), is used to describe some elite special operations forces around the world. The term has been applied to the Australian Defence Force's Special Air Service Regiment and four United States special operations forces units. Special mission units have been involved in high profile military operations such as the death of Osama Bin Laden and capture of Saddam Hussein.

United States
Special mission units are commanded and controlled by Joint Special Operations Command (JSOC) of U.S. Special Operations Command (USSOCOM). In addition to performing highly classified activities the special mission units are also tasked with "special missions", sometimes referring to unconventional warfare, counter-terrorist activities, direct action, Special reconnaissance, and/or black operations. So far, only three SMUs have been publicly disclosed: The Army's 1st Special Forces Operational Detachment—Delta, the Navy's Naval Special Warfare Development Group (DEVGRU), and the Air Force's 24th Special Tactics Squadron. Units from the Army’s 75th Ranger Regiment and 160th Special Operations Aviation Regiment (160th SOAR) are controlled by JSOC when deployed as part of JSOC Task Forces such as Task Force 121 and Task Force 145.

The Intelligence Support Activity (ISA) is also under JSOC and has been referred to as a special mission unit. The ISA collects specific target intelligence prior to SMU missions, and provides signals support, etc. during those mission. The army once maintained the ISA, but after the September 11 attacks, the Pentagon shifted direct control to Joint Special Operations Command at Fort Bragg, NC.

Government definition and acknowledgement
The United States defines the term Special Mission Unit as "a generic term to to represent a group of operations and support personnel from designated organizations that is task-organized to perform highly classified activities."

The U.S. government does not acknowledge which units specifically are designated as special missions units, only that they have special mission units under U.S. Special Operations Command. However, in the early 1990s then-Commander in Chief of U.S. Special Operations Command, General Carl Stiner identified both Delta Force and Seal Team 6 as permanently assigned special missions units in congressional testimoney and public statements. 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 (WMD). These units are on alert every day of the year and have worked extensively with their interagency counterparts."

Australia
The Australian Army's website describes the elite Special Air Service Regiment as being "a special missions unit with unique capabilities within the Australian Defence Force". The Regiment is a component of Australia's Special Operations Command (SOCOMD), and is tasked with conducting "sensitive strategic operations, special recovery operations, training assistance, special reconnaissance and precision strike and direct action".

The SASR currently has four sabre squadrons, known as 1, 2, 3 and 4 Squadron. 1, 2 and 3 Squadrons rotate through the two roles performed by the Regiment; one squadron conducts the counter terrorism/special recovery (CT/SR) role, and the remaining squadrons conduct the warfighting/reconnaissance role. 4 Squadron is responsible for collecting intelligence and also supports the Australian Secret Intelligence Service.

Notable operations
During the Iraq War United States' Task Force 121 was involved in Operation Red Dawn which led to the capture of Iraqi leader Saddam Hussein on December 13, 2003. Earlier that year on July 22, 2003 Task Force 20, led by Delta Force operators and supported by the 101st Airborne Division, were involved in a three hour firefight in Mosul, Iraq where both of Saddam's sons, Qusay and Uday were killed.

On May 2, 2011 Osama Bin Laden was killed in a CIA-led operation where U.S. Navy SEALs from DEVGRU's Red Squadron were flown into Abottabad, Pakistan by elements of 160th SOAR from Jalalabad, Afghanistan.