Infantry battalions are the heart and soul of the ground combat element. The mission of locating, closing with, and destroying the enemy with fire and maneuver and repelling the enemy's assault with fire and close combat lies with the "grunts". Marine infantry battalions often have limited organic equipment outside of small arms, infantry crew-served weapons (e.g., heavy machine guns, medium mortars, and anti-tank missiles), and a few light tactical trucks. Marine infantry primarily maneuvers by foot as light infantry, and must be supplemented with additional trucks to become motorized infantry or Amphibious Assault Vehicles to become mechanized infantry.
The mission of a tank battalion is to conduct operations ashore utilizing maneuver, armor protected firepower and shock action in order to close with and destroy the enemy, as well as provide expertise in anti-tank operations. Currently, tank battalions utilize the M1A1 Abramsmain battle tank and the M88A2Recovery Vehicle.
The mission of an armor unit is to conduct and support amphibious operations and other operations as required by landing and transporting to inland objectives the surface assault elements and their equipment, and by conducting light armored reconnaissance and limited offensive and defensive operations. When task-organized with infantry, tanks, and other forces, the battalion conducts combined arms operations as a separate maneuver element in support of the Marine Division. Currently, Assault Amphibian battalions utilize the Amphibious Assault Vehicle (AAVP-7A1). Although plans were in place to replace it with the Expeditionary Fighting Vehicle, the cancellation of the program is going to prolong use of the AAV. Light Armored Reconnaissance battalions use the LAV 25 series of vehicles. The Combat Assault Battalion is unique in that it combines both vehicles into a single battalion.
Headquarters battalions serve as the command and control nexus for a Marine division. They contain the administration, intelligence, operations, planning, logistics, communication, and public affairs control of the division.
Combat logistics battalions (CLB) provide combat service support for the GCE and ACE beyone their own organic capabilities. The battalions primarily provide motor transport and materiel handling (i.e., landing support) services, and limited engineer, maintenance, and supply services, to dedicated Regimental Combat Teams or Marine Expeditionary Units.
Maintenance battalions provide intermediate level (3d and 4th echelon) maintenance support for Marine Corps furnished (vice Navy, other service, or contractor provided) tactical ordnance (i.e., weapons and weapons systems), engineer, motor transport, communication-electronics, and general support (e.g., generators, refrigeration systems, water purification) equipment of the Marine Expeditionary Force (MEF).
Supply battalions provide supply support past that of organic unit supply. They provide all assets that a Marine unit might need, excepting fuels, water, and aviation repair parts provided from the Navy. Rations, repair parts, ammunition, personal equipment, and even entire end items are all provided by or through the supply battalions.
Medical battalions provide medical care beyond the immediate care of unit corpsmen. Often, these units act as field hospitals when on deployment. In garrison, they supplement naval hospitals at various Marine installations.
Dental battalions are responsible for the oral health of Marines and Sailors within the MAGTF. On deployment, they can also be used to support field hospitals per Bureau of Medicine and Surgery Instruction, when not performing dental roles. In garrison, they run dental health clinics at various Marine installations.
The LE battalions will be a force multiplier to the operating forces forward deployed by assisting in an array of missions from law enforcement, route regulation, humanitarian assistance, nonlethal weapons training, and military working dog employment. Marine Corps Bulletin 5400, released in September 2011, called for the reactivation of the 1st, 2nd, 3rd, and 4th Military Police Battalions, now designated as law enforcement battalions, in each Marine Expeditionary Force and Marine Forces Reserve. Three law enforcement battalions were activated in June 2012.
While these units are designated as companies, they are commanded by a Lt. Col. who is assisted by an executive officer and an executive staff (S-1,2,etc.). The company's organic platoons often operate independently and are normally commanded by a major (ANGLICO) or captain (FORECON).
Air Naval Gunfire Liaison companies (ANGLICO) provide Marine Air-Ground Task Force (MAGTF) commanders a liaison capability, with foreign area expertise, to plan, coordinate, and conduct terminal control of fires in support of joint, allied, and coalition forces.
Fleet Marine Force Reconnaissance (FORECON) companies provide Marine Air-Ground Task Force (MAGTF) commanders with deep reconnaissance and direct action capability.
With the exception of the Low Altitude Air Defense battalions, which are organic to the Marine Air Control Group of a Marine Aircraft Wing, and are a component of the Aviation Combat Element (ACE) of a Marine Air Ground Task Force (MAGTF), the battalions in this section perform missions either within the Operating Forces of the Marine Corps but outside the MAGTF structure, or within the Supporting Establishment.
Low Altitude Air Defense (LAAD) battalions are tasked with providing ground based air defense in support of the MAGTF. They are also able to be tasked as provisional infantry battalions. They are the only battalion within the Marine Aircraft Wing.
The Marine Raider battalions of the Marine Raider regiment provide the principal special operations combat capability of the Marine Corps Forces Special Operations Command in performing direct action, special reconnaissance, counter-terrorism, information operations, foreign internal defense, and unconventional warfare missions.
Special Mission battalions and battalion equivalent organizations
These battalions and organizations perform a wide range of specialized missions including: (1) CBRNE Consequence Management, (2) interior security of United States diplomatic posts to provide protection for classified information and equipment vital to U.S. national security, (3) Signals Intelligence, Information Assurance, and National-Tactical Integration activities, (4) physical security of naval nuclear vessels and weapons, (5) special operations intelligence support, and (6) special operations administrative, logistics, communications, EOD, Military Working Dog, and other operations support.
These battalions provide advanced training (i.e., beyond the scope of initial training provided by the Recruit Training battalions, Officer Candidates School, or other pre-commissioning programs (e.g., US Naval Academy). The scope of training provided includes: (1) Training and educating newly commissioned or appointed officers ... with particular emphasis on the duties, responsibilities and warfighting skills required of a rifle platoon commander, (2) Military Occupation Specialty (MOS) training for assault amphibian crewmen and combat engineers, and (3) individual and crew-served weapons and fieldcraft training for new Marines.
Provide reception, processing, and recruit training for enlisted personnel following initial entry into the Marine Corps. Provide training for Drill Instructors and officers entrusted with recruit training responsibilities.