Marine Air-Ground Task Force
Marine Air-Ground Task Forces form the fundamental structure of all United States Marine Corps operations. They always have the same four components; they differ in the size of each component.
- Command element
- Aviation combat element
- Ground combat element
- Combat service support element
|Organization||Typical command||Typical air component||Typical ground component||Typical support component|
|Marine Expeditionary Unit (MEU)||Colonel||Squadron (air forces)||Battalion||Group|
|Marine Expeditionary Brigade (MEB)||Brigadier general||composite Marine aircraft group||reinforced infantry regiment,||brigade service support group.|
|Marine Expeditionary Force (MEF)||Lieutenant general (major general as separate Forward)||1 or more Wing||1 or more Division||1 or more force service support groups.|
In recent years, the Marine missions have included a substantial amount of counterinsurgency and urban combat. While their ground combat equipment once focused principally on assault from the sea, they have had a number of assignments that may not have involved amphibious operations at all, but work as light infantry in urban environments. This has become more evident in some changed capabilities of the MAGTF elements.
The command element must be capable of working in joint and multinational operations.
Ground combat element
Marine vehicles and other equipment often is more flexible, in confined urban areas, than the larger, heavier Army equipment that is more flexible in an open battlefield. The Army, indeed, is developing a force mixture that includes lighter equipment.
The Marines have received priorities on lighter equipment, such as the first shipments of the M777 ultralightweight 155mm howitzer. T
Among the Marine concepts for urban warfare is the need to be able to neutralize cellular telephony used by insurgents as their primary means of communications. One example of dealing with electronics warfare in urban operations is the mobile electronics warfare system, the AN/ULQ-30.
Air combat element
Marine Aviation is far more closely tied to ground units than those of the Army. Essentially, aircraft, deployable from amphibious ships or minimal forward bases, replace the well-supplied artillery available to heavier Army units. While there are fixed-wing Marine aircraft on carriers and at shore bases, they are intended for support of the MAGTF, and Marines tend to scream when any part is reassigned, in the Unified Combatant Command model, to a Air Combatant Commander.
Marine armed helicopters of the AH-1 series are smaller than Army AH-64 Apache helicopters. The latter series, with their associated OH-58 Kiowa Warrior scout helicopters, are optimized for anti-tank warfare, which is not a primary Marine mission.
The AH-1 series, which is an extremely evolved variant of the first Vietnam-era armed helicopters, are easier to support from amphibious ships and austere forward bases, and, to provide infantry close air support, do not need extensive antitank systems.
Troop lift comes from the obsolete H-46 "Bullfrog" helicopters, officially Sea Knights. These will primarily be replaced by MV-22 Osprey tilt-rotor aircraft. The Marines also use some CH-53 heavy helicopters, primarily for equipment lift.
Marine Expeditionary Unit
This is the basic forward-deployed, at-sea Marine organization, teamed with a Navy Expeditionary Strike Group. Its support organization allows it to operate, unsupported, for 90 days of supplies and repair parts are normally provided aboard amphibious shipping, except for aviation ordnance, which is constrained to 15 days due to limits of amphibious shipping explosive material storage capabilities.
Most MEUs are designated "Special Operations Capable". This does not make them full-time special operations units under United States Special Operations Command; USSOCOM has a specific Marine Special Operations component. A MEU(SOC) has various augmentation, varying with specifics but variously including a U.S. Navy SEAL detachment, a tank unit, and other selected personnel and equipment, which allow it to conduct amphibious warfare and a variety of specialized missions of limited scope and duration. These additional missions include specialized demolition, clandestine reconnaissance and surveillance, raids, combat search and rescue, and enabling operations for followon forces. Doctrine states it may conduct limited special operations in extremis, when other forces are inappropriate or unavailable. For example, it may carry out hostage recovery when no more specialized force (e.g., Joint Special Operations Command) is available.
Expeditionary Strike Group
Marine Expeditionary Brigade
A composite unit of intermediate size, with organic support for 30 days of operations. It can function as part of a joint task force, as the lead echelon of the Marine expeditionary force (MEF), or alone.
1st Marine Expeditionary Brigade is permanently forward-deployed to Okinawa, and is a principal U.S. ground response element for the western Pacific, under United States Pacific Command. A provisional Marine brigade was a key reinforcing element in the early part of the Korean War, acting as "fire brigade" in holding the Pusan Perimeter. This Perimeter was the pocket into which U.S. and South Korean forces had been driven by the North Korean advance.
Marine Expeditionary Force
The largest Marine air-ground task force (MAGTF) and the Marine Corps principal warfighting organization, particularly for larger crises or contingencies. It can operate as a corps-level headquarters. A MEF contains one or more Marine divisions, Marine aircraft wings, and Marine force service support groups. It is prepared for sustained operations of 60 days. 
A MEF may also split into a forward echelon and a main headquarters, with the MEF commander at either location. The MEF Forward may prepare for the full MEF, or, as is the case in Iraq, operate as a stand-alone Marine or joint headquarters.
I Marine Expeditionary Force
Based at Camp Pendleton, California, this is the major command in the western U.S., under LTG Samuel Helland. It has a forward echelon currently functioning as the headquarters of Multinational Force-West in Iraq, commanded by MG John Kelly
Currently built around the 1st Marine Division, 3rd Marine Wing, and 1st Force Logistics Group, I MEF served as a corps-equivalent headquarters in the Gulf War, commanding two Marine divisions and attached Army units. Under the command of LTG Walter Boomer, had the major role of breaching the Iraqi defensive lines, and supporting the pan-Arab corps in the liberation of Kuwait City.