Like any other profession or industry private military and security contracting has its own specialized vocabulary. Some of it is straightforward and comprehensible, but much of it is not. Take the phrase "Tier Operator", for example.
The term is casually tossed around by people in the industry but nobody ever seems to be able to offer a precise definition. A casual explanation is that it refers to various categories of jobs for a security contractor. Some say it depends on the mission, rather the qualifications of the operator.
Years ago I asked Eric Prince, founder of Blackwater, at a conference for a definition and he said it came out of the special operations forces community. It is certainly in use there but I have yet to see an authoritative, official definition. The definition seems to change according to who you ask. Also, many security companies seem to have their ows set of qualifications for various tiers
To give one example, at the top of the heap Tier 1 jobs might require a current Secret security clearance and a minimum of eight years experience in the intelligence field. In this tier, one would list skills in such things as hostage rescue, communications, medic, close quarter battle, counterterrorist operations, and explosive ordnance disposal, to name just a few.
Tier 2 requires a minimum of eight years in law enforcement, or security operations, and a Secret security clearance. Skills listed are Executive/Close protection, reconnaissance and surveillance.
Tier 3 mainly lists skills and experience in field operations.
But a retired Army officer who used to do oversight on security contractors in Iraq just sent me two Power Point presentations that depict the tier system in use in Iraq. He notes that it means more to the State Department than the Pentagon.
Note that I can't say how old the first presentation is so I don't know if the companies it names are still in the various Tier categories or are currently working for the State or Defense Departments.
According to the State Department Tier System presentation the Tier 1's are folks detailed to support the Chief of Mission PSD [Protective Security Detail] support. According to the PP slide:
TIER 1 PSCs
Perform missions that directly support the COM
Examples: DOS personnel, Ambassadors, other diplomats, and CODELs
3 PSCs are considered Tier 1This includes Xe Services, formerly Blackwater, DynCorp, and Triple Canopy, who have all worked under the State Department's Worldwide personal Protective Services Contract (WPPS).
The Tier 2's support the other folks like USAID. Tier 2's were not allowed to provide PSD support to mission personnel.
TIER 2 PSCs
Perform missions that indirectly support the COM
Examples: USAID, IRD
These PSCs may also perform missions under contract with DOD
11 PSCs are considered Tier 2
The firms that provided Tier 2 operators were Sabre International Security, Blackwater, Unity Resources Group, Ronco Consulting Corporation, GardaWorld, Sallyport Global Holdings, Edinburgh International, Erinys, DynCorp International, and Janusian Security Risk Management Ltd.
The other Power Point presentation, dated March 2009, detailed contractors working for the Defense Department in Iraq during the winter of 2008 and 2009. It listed 27 DoD PSC Contractors with 7,704 employees. These were assigned to the Multi-National Force-Iraq and its various subordinate commands.
These firms included:
CSS Global
Falcon
Aegis
Reed
Blue Hackle
ERSM
Safenet
Erynis
USIS
MPRI
EODT
ArmorGroup
SAIC
Triple Canopy
MPRI
Threat Management
Agility
Reed
Skylike
SecurForce
Hart
CACI
SOC-SMG
Parsons
ERSM Ltd.
Sabre
Lincoln Group
Taos Industries
Not all of these would have been doing actual gun toting security work. For example, Lincoln Group was hired to do public relations. Taos Industries handles commercial and military procurement and supply of new components and replacement system parts.