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 Center (SAC) in teams called Special Operations Groups when full political deniability is required (clandestine missions).
Tier 1 units in US military
There are only four acknowledged Tier 1 special mission units in the United States military:
- DELTA Force (1st Special Forces Operational Detachment – Delta) – U.S. Army
- DEVGRU (Naval Special Warfare Development Group, Seal Team 6) – U.S. Navy
- 24th Special Tactics Squadron – U.S. Air Force
- Intelligence Support Activity (ISA) – CIA
Delta Force’s full name is 1st Special Forces Operational Detachment—Delta. It is also known as CAG (Combat Applications Group). The unit is founded in 1977, it is part of the US Joint Special Operations Command, based at Fort Bragg, North Carolina. Delta Force is one of the most secret operations units in the United States military. It belongs under the U.S. Army branch.
The U.S. Navy counterpart to Delta Force is DEVGRU or SEAL Team 6. Their personnel is taken from the NAVSPECWARCOM SEAL teams. They are JSOC Maritime counter-terrorism specialists trained to rescue hostages from ships, oil rigs, fight pirates, assault and exploit High-Value Targets (HVT) for inclusion in the High Payoff Target List (HPT).
24th Special Tactics Squadron
The 24th Special Tactics Squadron is one of the Special Tactics units of the United States Air Force Special Operations Command (AFSOC). It is the U.S. Air Force component of Joint Special Operations Command. It is Airforce’s counterpart to the Delta Force and DEVGRU.
Intelligence Support Activity (ISA)
The US Army Intelligence Support Activity (USA ISA or US ISA) is a US Army Special Ops unit that is part of the Joint Special Operations Command. It is tasked to collect actionable intelligence in advance of missions by other US special operations forces, especially 1st SFOD-D and DEVGRU in counter-terrorist operations.
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, Army 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.