III Marine Expeditionary Force
US Marine Corps Forces, Japan

The mission of III Marine Expeditionary Force is to plan, direct, and coordinate Marine Air-Ground Task Forces for employment in support of contingency plans and operations in the Western Pacific and Indian Ocean. The Commander, III MEF is also the commander of US Marine Corps Forces, Japan. If directed by the Secretary of Defense via the Commander in Chief, US Pacific Command, III MEF can activate a joint task force headquarters, Joint Task Force 505 (JTF-505), to respond to regional contingencies.

With the drawdown of US forces in Europe and Korea, III Marine Expeditionary Force is the only division-scale maneuver force stationed abroad. By the mid-2000s, it had approximately 17,000 officers and soldiers, accounting for 60 percent of all American servicemen stationed in Okinawa. It was mobilized during the Gulf War in 1990-1991 and in air-strikes against Iraq in 2003. The US forces in Okinawa, deployed under the Japan-US security alliance, keep an eye on the Far East as far as the Indian Ocean. Their presence in Okinawa is an indispensable element of the US global strategy, under which 100,000 troops are forward deployed in Asia.

The III Marine Expeditionary Force was a descendant of the I and III Marine Amphibious Corps (MAC), which were activated on 1 October 1942. On 15 April 1944, I MAC was redesignated as III MAC and was subsequently paired with the Navy's III Amphibious Force for joint operations in the Pacific theater. III MAC took part in some of the most significant battles in the war against Japan: the invasions of Saipan, Tinian, Iwo Jima, and Okinawa.

Following the termination of hostilities, III MAC was dispatched to northern China in September 1945, to accept the surrender of enemy units and to supervise the repatriation of Japanese military and civilians. The reduction of the American presence in China and post-war demobilization brought about the deactivation of the III Amphibious Corps on 10 June 1946.

A forward deployed amphibious force came about again with the activation of III Marine Expeditionary Force (MEF) in the Republic of Vietnam on 7 May 1965, which consisted of the 3rd Marine Division and the 1st Marine Aircraft Wing. III MEF was later redesignated as III Marine Amphibious Force (MAF). On 15 March 1966, Force Logistics Command was formed at Da Nang and joined the III MAF. Expansion of Marine Forces in Vietnam continued in 1966 with the arrival of the 1st Marine Division. By May 1967, the area under Marine control had expanded to more than 1,700 square miles, encompassing 183 villages, and increasing the number of civilians under Republic of Vietnam control by more than one million. In April 1971, the headquarters of III MAF left Vietnam for Okinawa.

On 12 April 1975, the 31st Marine Amphibious Unit (MAU), a task group of III MAF, executed Operation Eagle Pull, in which 287 US and foreign nationals were evacuated from Phnom Penh, Cambodia. Weeks later, the 9th Marine Amphibious Brigade (MAB), a task force of the III MAF, successfully extracted by helicopter more than 7,000 Americans and Vietnamese from Saigon, Vietnam during Operation Frequent Wind. In conjunction with the later operation, Marine detachments from III MAF provided security for US ships engaged in carrying Vietnamese refugees to Guam. Within days, Marines of III MEF were again called on to assist in the recovery of the USS Mayaguez from Cambodia. Elements of the 1st Battalion, 4th Marines; the 2nd Battalion, 4th Marines; and 9th Marines, were flown to an advanced staging of a joint US task force. There, they conducted a helicopter assault onto the Cambodian island of Koh Tang where the Mayaguez was being held. The crew and ship were recovered on 15 May 1975, and the III MEF units returned to Okinawa.

On 5 February 1988, the III MAF was redesignated to III Marine Expeditionary Force. III MEF units subsequently supported a host of contingency operations, and routinely participated in joint, combined and bilateral exercises with Asian and Pacific countries like Thailand, Korea, Australia, and the Philippines. Nearly 8,000 III MEF Marines deployed in support of Operations Desert Shield and Desert Storm in Southwest Asia in 1990-1991. III MEF units were instrumental in the success of Operation Sea Angel in Bangladesh in 1991, and during disaster relief operations in the Republic of the Philippines following the eruption of Mount Pinatubo in 1991. III MEF Marines provided disaster relief in the wake of the earthquake in Kobe, Japan in 1995.

Following the Tohoku earthquake and resulting tsunami in Japan in March 2011, III MEF activated Joint Task Force 505 and deployed personnel to assist in the voluntary evacuation of US nationals from the country during Operation Pacific Passage.