The United States Marine Corps serves as an amphibious force-in-readiness. Marines are trained to such a degree that many foreign governments consider US Marines to be shock troops. Today, it has three primary areas of responsibility as outlined in 10 U.S.C. § 5063, originally introduced under the National Security Act of 1947:
- The seizure or defense of advanced naval bases and other land operations to support naval campaigns;
- The development of tactics, technique, and equipment used by amphibious landing forces; and
- "Such other duties as the President may direct."
The quoted clause, while seemingly a consequence of the President's position as Commander-in-Chief, is a codification of the expeditionary duties of the Marine Corps. It derives from similar language in the Congressional Acts "For the Better Organization of the Marine Corps" of 1834, and "Establishing and Organizing a Marine Corps" of 1798. In 1951, the House of Representatives' Armed Services Committee called the clause "one of the most important statutory—and traditional—functions of the Marine Corps." It noted that the Corps has more often than not performed actions of a non-naval nature, including its famous actions in the War of 1812, at Tripoli, Chapultepec (during the Mexican-American War), numerous counter-insurgency, and occupational duties in Central America and East Asia, World War I and the Korean War. While these actions are not accurately described as support of naval campaigns nor as amphibious warfare, their common thread is that they are of an expeditionary nature, using the mobility of the Navy to provide timely intervention in foreign affairs on behalf of American interests.
In addition to its primary duties, the Marine Corps undertakes missions in support of the White House and the State Department. President Thomas Jefferson dubbed the Marine Band the "President's Own" for its role of providing music for state functions at the White House. In addition, Marines guard presidential retreats, including Camp David,[ and the Marines of the Executive Flight Detachment of HMX-1 provide VIP helicopter transport to the President and Vice President, using the call signs "Marine One" (when the President is aboard) and "Marine Two" (when the Vice President is aboard). By authority of the 1946 Foreign Service act, the Marines of the Marine Embassy Security Command provide security for American embassies, legations, and consulates at over 110 State Department posts overseas.
At its founding, the Marine Corps was composed of infantry serving aboard naval vessels and was responsible for the security of the ship and her crew by conducting offensive and defensive combat during boarding actions, and defending the ship's officers from mutiny; to the latter end, their quarters on ship were often strategically positioned between the officers' quarters and the rest of the vessel. Continental Marines, as they were known at the time, were also responsible for manning raiding parties, both at sea and ashore. The role of the Marine Corps has since expanded significantly; as the importance of its original naval mission declined with changing naval warfare doctrine and the professionalization of the Naval service, the Corps adapted by focusing on what were formerly secondary missions ashore. The Advanced Base doctrine of the early 20th century codified their combat duties ashore, outlining the use of Marines in the seizure of bases and other duties on land to support naval campaigns. The Marines would also develop tactics and techniques of amphibious assault on defended coastlines in time for use in World War II. Its original mission of providing shipboard security finally ended in the 1990s, when the last Marine security detachments were withdrawn from U.S. Navy ships.
While the Marine Corps does not employ any unique combat arms, it has, as a force, the unique ability to rapidly deploy a combined-arms task force to almost anywhere in the world within days. The basic structure for all deployed units is a Marine Air-Ground Task Force (MAGTF) that integrates a ground combat component, an air combat component, and a logistics combat component under a common command element. While the creation of joint commands under the Goldwater-Nichols Act has improved interservice coordination between the U.S. military services, the Corps' ability to permanently maintain integrated multi-element task forces under a single command provides a smoother implementation of combined-arms warfare principles.
The close integration of disparate Marine units stems from an organizational culture centered around the infantry. Every other Marine capability exists to support the infantry. Unlike many Western militaries, the Corps remained conservative against theories proclaiming the ability of new weapons to win wars independently. For example, Marine Aviation has always been focused on close air support and has remained largely uninfluenced by airpower theories proclaiming that strategic bombing can singlehandedly win wars.
This focus on the infantry is matched with the fact that "Every Marine is a rifleman," emphasizing the infantry combat abilities of every Marine. All enlisted Marines receive training first and foremost as a rifleman; all officers receive training as infantry platoon commanders.The value of this culture has been demonstrated many times throughout history. For example, at Wake Island, when all the Marine aircraft were shot down, their pilots continued the fight as riflemen, leading supply clerks and cooks in a final defensive effort.
The amphibious assault techniques developed for World War II evolved, with the addition of air assault and maneuver warfare doctrine, into the current "Operational Maneuver from the Sea" doctrine of power projection from the seas. The Marines are credited with the development of helicopter insertion doctrine and were the earliest in the American military to widely adopt maneuver-warfare principles, which emphasize low-level initiative and flexible execution. As a result, a large degree of initiative and autonomy is expected of junior Marines, particularly the NCOs, (corporals and sergeants), as compared with many other military organizations. The Marine Corps emphasizes authority and responsibility downward to a greater degree than the other military services. Flexibility of execution is implemented via an emphasis on "commander's intent" as a guiding principle for carrying out orders; specifying the end state but leaving open the method of execution.
The U.S. Marine Corps relies on the U.S. Navy for sealift to provide its rapid deployment capabilities. In addition to basing a third of the Marine Corps Operating Forces in Japan, Marine Expeditionary Units (MEU), smaller MAGTF, are typically stationed at sea. This allows the ability to function as first responders to international incidents. The U.S. Army now maintains light infantry units capable of rapid worldwide deployment, though they do not match the combined-arms integration of a MAGTF, nor do they have the logistical training that the Navy provides.For this reason, the Corps is often assigned to non-combat missions such as the evacuation of Americans from unstable countries and humanitarian relief of natural disasters. In larger conflicts, Marines act as a stopgap, to get into and hold an area until larger units can be mobilized. The Corps performed this role in World War I, the Korean War, and Operation Desert Storm, where Marines were the first significant combat units deployed from the United States and held the line until the country could mobilize for war.
Global War on Terrorism
Following the September 11, 2001 attacks President Bush declared a War on Terrorism. The stated objective of the Global War on Terror is "the defeat of al Qaeda, other terrorist groups and any nation that supports or harbors terrorists". Since that time the United States Marine Corps, along with other military and federal agencies, has engaged in global operations including Operation Iraqi Freedom and Operation Enduring Freedom as part of that mission.
Operation Enduring Freedom
Marines and other U.S. forces began staging in Uzbekistan on the border of Afghanistan as early as October, 2001 in preparation for the invasion of Afghanistan.The 15th and 26th Marine Expeditionary Units were the first conventional forces into Afghanistan in support of Operation Enduring Freedom in November of 2001 when they seized an airfield outside of Khandahar. Since then Marine battalions and squadrons have been rotating through, engaging Taliban and Al-Qaeda forces. In 2002, Combined Joint Task Force - Horn of Africa (CJTF-HOA) was stood up at Camp Lemonier to provide regional security. Despite transferring overall command to the U.S. Navy in 2006 the Marines have continued to operate in the Horn of Africa into 2007.
Operation Iraqi Freedom
Most recently, the Marines have served prominently in Operation Iraqi Freedom. The I Marine Expeditionary Force, along with the Army's 3rd Infantry Division, spearheaded the 2003 invasion of Iraq.During the occupation of Iraq, Marines spearheaded both assaults on the city of Fallujah in April and November 2004, also known as Operation Phantom Fury.Their time in Iraq has also courted controversy with the Haditha killings and the Hamdania incident.They currently continue to operate throughout Iraq.
Relationship with other services
The Marine Corps combat capabilities in some ways overlap those of the U.S. Army, the latter having historically viewed the Corps as encroaching on the Army's capabilities and competing for funding, missions, and renown. The attitude dates back to the founding of the Continental Marines, when General George Washington refused to allow the initial Marine battalions to be drawn from among his Continental Army. Most significantly, in the aftermath of World War II, Army efforts to restructure the American defense establishment included the dissolution of the Corps and the folding of its capabilities into the other services. Leading this movement were such prominent Army officers as General Dwight D. Eisenhower and Army Chief of Staff George C. Marshall.
The Marine Corps is a partner service with the U.S. Navy under the Department of the Navy. As a result, the Navy and Marine Corps have a close relationship, more so than with other branches of the United States military. Whitepapers and promotional literature of the 20th century have commonly used the phrase "Navy-Marine Corps Team".Both the Chief of Naval Operations (CNO) and Commandant of the Marine Corps, heads of their respective services, report directly to the Secretary of the Navy (SECNAV), a civilian who heads the Department of the Navy.
Cooperation between the two services begins with the training and instruction of Marines. The Corps receives a significant portion of its officers from the United States Naval Academy and Naval Reserve Officer Training Corps (NROTC). NROTC are staffed by Marines alongside naval officers. Marine Corps drill instructors contribute to training of naval officers in the Navy's Officer Candidate School. Marine aviators are trained in the Naval Aviation training pipeline.
Training alongside each other is viewed as critical, as the Navy provides transport, logistical, and combat support to put Marine units into the fight. Navy aircraft carriers typically deploy with a Marine F/A-18 Hornet squadron alongside Navy squadrons. Since the Marines do not train chaplains or medical personnel, officers and enlisted sailors from the Navy fill these roles. Some of these sailors, particularly Hospital Corpsmen, generally wear Marine uniforms emblazoned with Navy insignia and markings in order to be noticeably distinct to compatriots but generally indistinguishable to enemies. Conversely, the Marine Corps is responsible for conducting land operations to support naval campaigns, including the seizure of naval and air bases. Both services operate a network security team in conjunction.
Finally, there are several traditional connections between the two services. Marine Corps Medal of Honor recipients wear the Navy variant of the award; Marines also may be awarded the Navy Cross. The Navy's Blue Angels flight demonstration team includes at least one Marine pilot, and is supported by a Marine C-130 Hercules aircraft. In cities with Navy and Marine Corps presence, social activities are often conducted together, for example with the Navy/Marine ball in San Diego.
Air-ground task forces
Today, the basic framework for deployable Marine units is the Marine Air-Ground Task Force (MAGTF), a flexible structure of varying size. A MAGTF integrates a ground combat element (GCE), an air combat element (ACE), and a logistics combat element (LCE) under a common command element (CE). A MAGTF can operate independently or as part of a larger coalition. It is a temporary organization formed for a specific mission and dissolved after completion of that mission. The MAGTF structure reflects a strong tradition in the Corps towards self-sufficiency and a commitment to combined arms, both essential assets to an expeditionary force often called upon to act independently in discrete, time-sensitive situations. The history of the Marine Corps as well has led to a wariness of overreliance on its sister services, and towards joint operations in general.
A MAGTF varies in size from the smallest, a Marine Expeditionary Unit (MEU), based around a reinforced infantry battalion and a composite squadron, up to the largest, a Marine Expeditionary Force (MEF), which ties together a Division, an Air Wing, and a Logistics Group under a MEF Headquarters Group. There are usually three MEUs assigned to each of the Navy's Atlantic and Pacific Fleets, with a seventh MEU based on Okinawa. While one MEU is on deployment, one MEU is training to deploy and one is standing down, resting its Marines and refitting. Each MEU is rated as capable of performing special operations.
The three Marine Expeditionary Forces are:
- I Marine Expeditionary Force located at Camp Pendleton, California
- II Marine Expeditionary Force located at Camp Lejeune, North Carolina
- III Marine Expeditionary Force located at Camp Courtney, Okinawa, Japan
Although the notion of a Marine special forces contribution to the U.S. Special Operations Command (USSOCOM) was considered as early as the founding of USSOCOM in the 1980s, it was resisted by the Marine Corps. Then-Commandant Paul X. Kelley expressed the popular belief that Marines should support Marines, and that the Corps should not fund a special warfare capability that would not support Marine operations. However, much of the resistance from within the Corps dissipated when Marine leaders watched the Corps' 15th and 26th MEU(SOC)s "sit on the sidelines" during the very early stages of Operation Enduring Freedom while other special operations units actively engaged in operations in Afghanistan.After a three-year development period, the Corps agreed in 2006 to supply a 2,600-strong unit, Marine Forces Special Operations Command (MARSOC), which would answer directly to USSOCOM.