The term Tier 1 (Tier One) in the United States military is often referred to as the Special Mission Unit or Special Missions Unit (SMU). It is particularly used to describe some military Special Operations Forces. Special mission units have been involved in high-profile military operations such as Operation Neptune Spear (the killing of Osama Bin Laden).
Tier 1 Special Mission Units are closed teams that are staffed by invitation. They fall under the ultra-secret Joint Special Operations Command (JSOC) which is within USSOCOM. They are the best of the best of the best. They frequently staff teams coordinated and commanded by the CIA’s Special Activities Division in teams called Special Operations Groups when full political deniability is required (clandestine missions).
Tier 1 units<
There are only four acknowledged Tier 1 SMUs:
- DELTA Force (1st Special Forces Operational Delta) – U.S. Army
- DEVGRU (Naval Special Warfare Development Group, Seal Team Six) – U.S. Navy
- 24th Special Tactics Squadron – U.S. Air Force
- Intelligence Support Activity (ISA) – CIA
The operators who are assigned to the Tier 1 units are the creme de la creme of special operations forces, usually, admittance into Tier 1 units is only possible after service in a Tier 2 unit. For example, as for DEVGRU, one must also be ex-spec ops, unlike regular SEAL Teams which admittance does not require prior military service. In Delta Force, most of the unit comes from either RB or SF, but it’s not a prerequisite. Members have come from traditional infantry and non-infantry units. The only requirement is that if you are not 11B or 18 series after your initial 3-year commitment you will reclass to one of these specialties.
The skills set that Tier 1 applicants would have due to prior service in Tier 2 units would be impeccable marksmanship skills, explosives skills and knowledge of military strategy tactics, etc. Once fully trained as a Tier 1 spec ops member the soldier would have been trained in psychological training to resist torture/interrogation and trained in evasion tactics such as Survival, Evasion, Resistance and Escape (SERE) training.
At some points, there is also possible that members of the Tier 2 units, like those from the Army’s 75th Ranger Regiment, Special Forces, and 160th SOAR are controlled by JSOC when deployed as part of JSOC Task Forces such as Task Force 121 and Task Force 145.