Marine Expeditionary Unit 31

Marine Expeditionary Unit 31
Unit name	Marine Expeditionary Unit 31
Country	United States of America
Allegiance	United States Pacific Command
Branch	United States Marine Corps
Type	Marine expeditionary unit
Role	Amphibious assault, crisis response, special operations support
Size	~2,200 personnel
Garrison	Marine Corps Base Camp Pendleton
Nickname	"31st MEU"
Motto	"Swift, Silent, Deadly"

Marine Expeditionary Unit 31 is a Marine Air-Ground Task Force-sized rapid-response force assigned to the I Marine Expeditionary Force and based at Marine Corps Base Camp Pendleton. As an expeditionary element, it integrates command, ground combat, aviation, and logistics components drawn from units such as the 1st Marine Division, 3rd Marine Aircraft Wing, and Combat Logistics Regiment 1. The unit routinely embarks on Amphibious Ready Group ships and participates in operations across the Indo-Pacific region, projecting power from sea to shore.

History

The unit traces its lineage through post-World War II amphibious organizations that evolved during the Cold War and Vietnam War eras into the modern MEU concept promulgated by the United States Pacific Command and United States Central Command. During the 1990s, the unit participated in contingency operations associated with the Gulf War aftermath and humanitarian missions linked to the 1994 Rwandan genocide relief architecture. In the Global War on Terrorism, the MEU deployed in support of Operation Enduring Freedom and Operation Iraqi Freedom, conducting raids, noncombatant evacuation operations like those associated with crises in Benghazi-adjacent regions, and maritime security patrols near the Strait of Hormuz. The MEU has also engaged in cooperative exercises tied to the Asia-Pacific Economic Cooperation security initiatives and responded to natural disasters such as the tsunami relief efforts coordinated after the 2004 Indian Ocean earthquake and tsunami.

Organization and Role

The MEU is organized as a Marine Air-Ground Task Force with a Command Element drawn from I Marine Expeditionary Force staff officers, a Ground Combat Element typically formed around a reinforced infantry battalion from the 1st Marine Division, an Aviation Combat Element sourced from the 3rd Marine Aircraft Wing including tiltrotor and rotary-wing assets from squadrons that have supported operations like Operation Iraqi Freedom, and a Logistics Combat Element provided by units within Combat Logistics Regiment 1. Its core role conforms to amphibious power projection defined by doctrines promulgated in the Marine Corps Doctrinal Publication 1 and the National Defense Strategy maritime posture, enabling crisis response, forcible entry, and maritime interdiction operations in theaters ranging from the Western Pacific to the Persian Gulf.

Deployments and Operations

The unit has been forward-deployed aboard Wasp-class amphibious assault ships and San Antonio-class amphibious transport docks participating in Operation Southern Watch enforcement, Operation Restore Hope-style humanitarian assistance, and sustained presence missions near hotspots including the Korean Peninsula and the South China Sea. It conducted noncombatant evacuation operations during regional instability linked to the Arab Spring and supported coalition efforts in counterinsurgency environments alongside Coalition Forces Land Component Command elements. The MEU has executed maritime interdiction operations in coordination with the United States Fifth Fleet and United States Seventh Fleet, participated in security cooperation initiatives with partners such as the Japan Self-Defense Forces, the Royal Australian Navy, and the Republic of Korea Navy, and contributed to multinational exercises including RIMPAC and Talisman Sabre.

Training and Exercises

Preparation follows the MEU pre-deployment workup series including the Unit Deployment Program aligned with Marine Corps Combat Readiness Evaluation standards, culminating in a Certification Exercise validated by the Commandant of the Marine Corps and regional combatant commanders. The unit trains in ship-to-shore movements with amphibious shipping platforms similar to those used in Exercise Rim of the Pacific, practices close air support coordination with units drawing on assets familiar from Operation Enduring Freedom, and conducts urban operations and direct action rehearsals reflecting tactics from the Special Operations Capable MEU construct. Interoperability training has been performed with allies during bilateral exercises such as Cobra Gold, Malabar, and trilateral maneuvers involving the Navy Expeditionary Combat Command.

Equipment and Capabilities

The MEU fields equipment consistent with expeditionary maneuver warfare: infantry formations equipped with variants of the M27 Infantry Automatic Rifle and the M4 carbine, armored reconnaissance elements using vehicles comparable to the Light Armored Vehicle family, and breaching and engineering assets fielded alongside logistics platforms akin to the Medium Tactical Vehicle Replacement. Aviation components deploy MV-22 Osprey tiltrotors, AH-1Z Viper attack helicopters, UH-1Y Venom utility helicopters, and may task fixed-wing support such as the F-35B Lightning II from amphibious ships. The logistics element provides sustainment through equipment analogous to the Expeditionary Fast Transport and maritime prepositioning elements, enabling extended littoral operations.

Notable Commanders and Personnel

The MEU’s commanders have traditionally been colonels who later advanced to flag billets within organizations like the I Marine Expeditionary Force and the United States Indo-Pacific Command staff. Alumni have included officers who served in joint assignments at the Joint Chiefs of Staff and in interagency posts at the Department of Defense and the United States State Department. Enlisted leaders have progressed to senior enlisted roles within formations such as Marine Forces Pacific and have received decorations associated with combat deployments, including awards comparable to the Navy Cross and the Bronze Star Medal.

Insignia and Traditions

The unit’s insignia follows Marine expeditionary symbology featuring elements reflecting amphibious heritage tied to traditions observed since the Banana Wars era and the Guadalcanal Campaign. Ceremonial practices include commemorations on anniversaries linked to the I Marine Expeditionary Force lineage and observances alongside allied partners during Veterans Day and joint remembrance activities. Unit customs incorporate ethos passed down through Marine Corps lore such as the amphibious doctrine promulgated after World War II and the operational art reflected in the Little Wars concept.

Category:United States Marine Corps units