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United States Marine Corps

Main article
Leadership
Secretary of the Navy
Commandant of the Marine Corps
Sergeant Major of the Marine Corps
Major Commands
Organization of the Marine Corps
I Marine Expeditionary Force
II Marine Expeditionary Force
III Marine Expeditionary Force
Marine Forces Reserve
MARSOC
Headquarters Marine Corps
Personnel
Officer Insignia
Enlisted Insignia
Famous Marines
Uniforms & Equipment
Uniforms
Badges
Weapons
Vehicles & Aircraft
Structure
Marine Air-Ground Task Force
Bases
Battalions
Marine aviation
Expeditionary units
History and Traditions
Marine Corps history
Marines' hymn
Marine Band
Marine One
Marine Flag
Eagle, Globe, and Anchor

The United States Marine Corps (USMC) is a branch of the United States military responsible for providing power projection from the sea,^[1] using the mobility of the U.S. Navy to rapidly deliver combined-arms task forces. While administratively under the Department of the Navy,^[2][3] the US Marine Corps is a separate branch of the military, often working closely with US Naval forces for training, transportation, and logistic purposes.

Originally organized as the Continental Marines on 10 November 1775 as naval infantry, the Marine Corps has evolved in its mission with changing military doctrine and American foreign policy. The Marine Corps has served in every American armed conflict including the Revolutionary War. It attained prominence in the 20th century when its theories and practice of amphibious warfare proved prescient and ultimately formed the cornerstone of the Pacific campaign of World War II.^[4] By the mid 20th century, the Marine Corps had become the dominant theorist of amphibious warfare.^[5][6][7] Its ability to respond rapidly to regional crises has made it, and continues to make it, an important body in the implementation and execution of American foreign policy.^[8]

The United States Marine Corps, with 180,000 active duty and 40,000 reserve Marines as of 2005, is the smallest of the United States' armed forces in the Department of Defense (the Coast Guard, about one fifth the size of the Marine Corps, is under the Department of Homeland Security). The Corps is nonetheless larger than the entire armed forces of many significant military powers; for example, it is larger than the active duty Israel Defense Forces.^[9][10]

The United States Marine Corps serves as an amphibious force-in-readiness. 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.^[11]

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.^[12] In addition, Marines guard presidential retreats, including Camp David,^[13] 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 Marine security guards of the Marine Embassy Security Command provide security for American embassies, legations, and consulates at over 110 State Department posts overseas.^[14]

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.^[15] 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, as a force, has 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 inter-service 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.^[4]

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 some 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 air power theories proclaiming that strategic bombing can singlehandedly win wars.^[15]

This focus on the infantry is matched with the doctrine that "Every Marine is a rifleman," a focus of Commandant Alfred M. Gray, Jr., emphasizing the infantry combat abilities of every Marine. All enlisted Marines, regardless of military specialization, receive training as a rifleman; all officers receive training as infantry platoon commanders.^[16] 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, pilots continued the fight as ground officers, leading supply clerks and cooks in a final defensive effort.^[17]

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.^[1] 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.^[18]

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.^[4] For this reason, the Marine 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, and the Korean War, where Marines were the first significant combat units deployed from the United States and held the line until the country could mobilize for war.^[19]

Main article: History of the United States Marine Corps

The United States Marine Corps traces its institutional roots to the Continental Marines of the American Revolutionary War, formed at Tun Tavern in Philadelphia, by a resolution of the Continental Congress on November 10, 1775, a date regarded and celebrated as the date of the Marine Corps' "birthday". At the end of the American Revolution in 1783, both the Continental Navy and Continental Marines were disbanded, and although individual Marines were enlisted for the few American naval vessels left, the institution itself would not be resurrected until 1798. In preparation for the Naval War with France, Congress created the United States Navy and Marine Corps.^[20] The U.S. Marines' most famous action of this period occurred during the First Barbary War (1801–1805) against the Barbary pirates,^[21] when William Eaton and First Lieutenant Presley O'Bannon led seven Marines and 300 Arab and European mercenaries in an effort to capture Tripoli. Though they only reached Derna, the action at Tripoli has been immortalized in the Marines' hymn and the Mameluke Sword carried by Marine officers.^[22]

During the War of 1812, Marine naval detachments took part in the great frigate duels that characterized the war, which were the first American victories in the conflict. Their most significant contributions came at the Battle of Bladensburg and the defense of New Orleans. At Bladensburg, they held the line after the Army and militias retreated, and although eventually defeated, they inflicted casualties on the British and delayed their march to Washington, D.C. At New Orleans, the Marines held the center of Gen. Andrew Jackson's defensive line. By the end of the war, the Marines had acquired a well-deserved reputation as expert marksmen, especially in ship-to-ship actions.^[22]

After the war, the Marine Corps fell into a depression. The third and fourth commandants were court-martialed. However, the appointment of Archibald Henderson as its fifth commandant in 1820 breathed new life into the Corps; he would go on to become the Corps' longest-serving commandant. Under his tenure, the Corps took on expeditionary duties in the Caribbean, the Gulf of Mexico, Key West, West Africa, the Falkland Islands, and Sumatra. Commandant Henderson is credited with thwarting President Andrew Jackson's attempts to combine and integrate the Marine Corps with the Army.^[22] Instead, Congress passed the Act for the Better Organization of the Marine Corps in 1834, stipulating that the Corps was part of the Department of the Navy as a sister service to the U.S. Navy.^[23] This would be the first of many times that Congress came to the aid of the Marines.

When the Seminole Wars of 1835 broke out, Commandant Henderson volunteered the Marines for service, himself personally leading two battalions, nearly half of the entire Corps, to war. A decade later, in the Mexican–American War (1846–1848), the Marines made their famed assault on Chapultepec Palace, an imposing complex overlooking Mexico City. The Marines were placed on guard duty at the Mexican Presidential Palace, hence the phrase "The Halls of Montezuma" in the Marines' hymn. In the 1850s, the Marines would further see service in Panama and Asia, escorting Matthew Perry's East India Squadron on its historic trip to the Far East. Colonel Archibald Henderson is known affectionately as "The Grand Old Man" of the Marine Corps, based on his many contributions during his 39 years as Commandant.^[24]

Despite their vast service in foreign engagements, the Marine Corps played only a minor role in the Civil War (1861–1865); their most important task was blockade duty. As more and more states seceded from the Union, about half of the officers in the Marine Corps also left the Union to join the Confederacy and form The Confederate States Marine Corps (CSMC)(a branch of the Confederate Navy, was established by the Confederate Congress on March 16, 1861). Without most of its officers, the remaining Marines were few and inexperienced. The battalion of recruits formed for the First Battle of Bull Run (First Manassas) performed poorly, retreating with the rest of the Union forces. The Confederate Congress authorized the formation of a Marine Corps of its own, to be made up of ten companies, but this organization had little impact on the war.^[19]

The remainder of the 19th century was marked by declining strength and introspection about the mission of the Marine Corps. The U.S. Navy's transition from sail to steam put into question the need for Marines on naval ships. Meanwhile, Marines served as a convenient resource for interventions and landings to protect American lives and interests overseas. The Corps was involved in over 28 separate interventions in the 30 years from the end of the American Civil War to the end of 19th century, including China, Formosa, Japan, Nicaragua, Uruguay, Mexico, Korea, Panama, Hawaii, Egypt, Haiti, Samoa, Argentina, Chile, and Colombia. They would also be called upon to stem political and labor unrest within the United States.^[25] During this period, war correspondent Richard Harding Davis coined the phrase "The Marines have landed and have the situation well in hand." Under Commandant Jacob Zeilin's tenure, Marine customs and traditions took shape: the Corps adopted the Marine Corps emblem on November 19, 1868. It was also during this time that "The Marines' Hymn" was first heard. Around 1883, the Marines adopted their current motto "Semper Fidelis" (Latin: Always Faithful).^[22]

John Philip Sousa, the musician and composer, enlisted as a Marine apprentice at the age of 13, serving from 1867 until 1872. He would later return to Corps service from 1880 to 1892 as the leader of the U.S. Marine Band (The President's Own). (His father, John Antonio Sousa, had been a trombonist in the same band.)

During the Spanish–American War (1898), Marines led U.S. forces ashore in the Philippines, Cuba, and Puerto Rico, demonstrating their readiness for deployment. At Guantánamo Bay, Cuba, the Marines seized an advanced naval base that remains in use today by the U.S. Navy. Between 1899 and 1916, the Corps continued its record of participation in foreign expeditions, including the Philippine-American War, the Boxer Rebellion in China (1899–1901), Panama, the Cuban Pacifications, the Perdicaris Incident in Morocco, Veracruz (Mexico), Haiti, Santo Domingo (Dominican Republic), and in Nicaragua. In the 1900s and 1910s, the seizure of advance naval bases entered Marine Corps doctrine with the formation of the Marine Corps Advanced Base School and the Advanced Base Force, the prototype of the Fleet Marine Force.^[24]

Throughout the first half of the 20th century, before and after World War I, Marines saw action throughout Central America, including Haiti and Nicaragua. These actions became known as the "Banana Wars" after the principal export of those countries. The experiences gained in counter-insurgency and guerrilla operations during this period were consolidated into the Small Wars Manual.^[26]

During World War I, battle-tested, veteran Marines served a central role in the U.S. late entry into the conflict. Unlike the U.S. Army, the Marine Corps had a deep pool of officers and NCOs with battle experience, and experienced a relatively smaller expansion. Here, the Marines fought their celebrated battle at Belleau Wood, then the largest in the history of the Corps; it created the Marines' reputation in modern history. Rallying under the battle cries of "Retreat? Hell, we just got here!" (Captain Lloyd W. Williams) and "Come on, you sons of bitches, do you want to live forever?" (GySgt. Dan Daly), the Marines drove German forces from the area. While its previous expeditionary experiences had not earned it much acclaim in the Western world, the Marines' fierceness and toughness earned them the respect of the Germans, who rated them of stormtrooper quality.Though Marines and American media reported that Germans had nicknamed them Teufel Hunden as meaning "Devil Dogs," there is no evidence of this in German records and since Teufelshunde would be the proper German phrase, it was possibly American propaganda. Nevertheless, the name stuck.^[27] The Corps had entered the war with 511 officers and 13,214 enlisted personnel, and by November 11, 1918 had reached a strength of 2,400 officers and 70,000 men.^[28]

Between the World Wars, the Marine Corps was headed by Commandant John A. Lejeune. Under his leadership, the Corps presciently studied and developed amphibious techniques that would be of great use in World War II. Many officers, including Lt. Col. Earl Hancock "Pete" Ellis, foresaw a war in the Pacific with Japan and took preparations for such a conflict. While stationed in China, then-Lt. Col. Victor H. Krulak observed Japanese amphibious techniques in 1937. Through 1941, as the prospect of war grew, the Corps pushed urgently for joint amphibious exercises and acquired amphibious equipment such as the Higgins boat which would prove of great use in the upcoming conflict.^[29]

In World War II, the Marines played a central role in the Pacific War; the Corps expanded from two brigades to two corps with six divisions and five air wings with 132 squadrons. In addition, 20 defense battalions and a parachute battalion were set up.^[30] The battles of Guadalcanal, Tarawa, Cape Gloucester, Saipan, Peleliu, Iwo Jima, and Okinawa saw fierce fighting between U.S. Marines and the Imperial Japanese Army.

During the battle of Iwo Jima, photographer Joe Rosenthal took the famous photograph Raising the Flag on Iwo Jima of five Marines and one Navy corpsman raising the American flag on Mt. Suribachi. Secretary of the Navy James Forrestal, who had come ashore earlier that day to observe the progress of the troops, said of the flag raising on Iwo Jima, "...the raising of that flag on Suribachi means a Marine Corps for the next five hundred years." The acts of the Marines during the war added to their already significant popular reputation. The USMC War Memorial in Arlington, Virginia was dedicated in 1954. By war's end, the Corps had grown to include six divisions, five air wings, and supporting troops totaling about 485,000. Nearly 87,000 Marines were casualties during World War II and 82 received the Medal of Honor^[31] (including nearly 20,000 killed). 2,274 Marines were POWS {2,270 by the Japanese and 4 by the Germans}; 1,756 returned to the USA. 268 known to have died and 250 known to have been captured but otherwise unaccounted for and presumed to have died. See [1].

Despite Secretary Forrestal's prediction, the Corps faced an immediate institutional crisis following the war. Army generals pushing for a strengthened and reorganized defense establishment also attempted to fold the Marine mission and assets into the Navy and Army. Drawing on hastily assembled Congressional support, the Marine Corps rebuffed such efforts to dismantle the Corps, resulting in statutory protection of the Marine Corps in the National Security Act of 1947.^[32] Shortly afterward, in 1952 the Douglas-Mansfield Bill afforded the Commandant an equal voice with the Joint Chiefs of Staff on matters relating to the Marines and established the structure of three divisions and air wings that remains today. This allowed the Corps to permanently maintain a division and air wing in the Far East and participate in various small wars in Southeast Asia—in the Tachen Islands, Taiwan, Laos, Thailand, and South Vietnam.^[4]

The Korean War (1950–1953) saw the hastily formed Provisional Marine Brigade holding the defensive line at the Pusan Perimeter. To execute a flanking maneuver, General Douglas MacArthur called on Marine air and ground forces to make an amphibious landing at Inchon. The successful landing resulted in the collapse of North Korean lines and the pursuit of North Korean forces north near the Yalu River until the entrance of the People's Republic of China into the war. Chinese troops surrounded, surprised and overwhelmed the overextended and outnumbered American forces. However, unlike the Eighth Army, which retreated in disarray, the X Corps, which included the 1st Marine Division and the Army 7th Infantry Division, regrouped and inflicted heavy casualties during their fighting withdrawal to the coast. Now known as the Battle of Chosin Reservoir, it entered Marine lore as an example of toughness and resolve. Marines would continue a battle of attrition around the 38th Parallel until the 1953 armistice.^[33] The Korean War saw the Corps expand from 75,000 regulars to a force, by the end of the conflict in 1953, of 261,000 Marines, most of whom were reservists. 30,544 Marines were killed or wounded during the war and 42 were awarded the Medal of Honor.^[34]

The Marine Corps served an important role in the Vietnam War by partaking in such battles as Da Nang, Hue City, and Khe Sanh. Individuals from the USMC operated in the Northern I Corps Regions of South Vietnam. While there, they were constantly engaged in a guerilla war against the National Front for the Liberation of South Vietnam (NLF) and an intermittent conventional war against the North Vietnamese Army (NVA). Portions of the Corps were responsible for the less-known combined action program (CAC) that implemented unconventional techniques for counter-insurgency (COIN) and worked as military advisors to the Republic of Vietnam Marine Corps.

Vietnam was the longest war for Marines; by its end, 13,091^[35] were killed in action, 51,392 were wounded, and 57 Medals of Honor were awarded.^[36][37] Due to policies concerning rotation, more Marines were deployed for service during Vietnam than World War II.^[38] The USMC presence was withdrawn in 1971, and returned briefly in 1975 to evacuate Saigon and in an attempt to rescue the crew of the Mayagüez.^[39] While recovering from Vietnam, the Corps hit a detrimental low point in its service history caused by courts-martial and Non-Judicial Punishments related partially to increased Unauthorized Absences and Desertions during the war. Overhauling of the Corps began in the late 1970s when discharge policies for inadequate Marines relaxed, resulting in the removal of only the most delinquent. Once quality of new recruits improved, the Corps could focus on reforming the NCO Corps, a vital functioning part of its forces.^[4]

After Vietnam, the Marines resumed their expeditionary role, participating in the 1980 Iran hostage rescue attempt Operation Eagle Claw, the invasion of Grenada (Operation Urgent Fury) and the invasion of Panama (Operation Just Cause). On October 23, 1983, the Marine headquarters building in Beirut, Lebanon was bombed, causing the highest peacetime losses to the Corps in its history (220 Marines and 21 other service members of the 24th Marine Expeditionary Unit were killed) and leading to the American withdrawal from the country. The year of 1990 saw Marines of the Joint Task Force Sharp Edge save thousands of lives by evacuating the British, French and American Nationals from the violence of the Liberian Civil War. During the Persian Gulf War (1990–1991), Marine task forces formed the initial core for Operation Desert Shield, while U.S. and Coalition troops mobilized, and later liberated Kuwait in Operation Desert Storm.^[22] U.S. Marines participated in combat operations in Somalia (1992–1995) during Operations Restore Hope, Restore Hope II, and United Shield to provide humanitarian relief.^[40]

Main article: War on Terrorism

Following the September 11, 2001 attacks President George W. Bush announced 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".^[41] Since that time the United States Marine Corps, along with other military and federal agencies, has engaged in global operations including Operation Enduring Freedom, Operation Iraqi Freedom, and other areas of the world, as part of that mission.

Main article: 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.^[42] 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.^[43] 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.^[44] Despite transferring overall command to the U.S. Navy in 2006 the Marines have continued to operate in the Horn of Africa into 2007.^[45]

Main article: Iraq War

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.^[46] 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.^[47] Their time in Iraq has also courted controversy with the Haditha killings and the Hamdania incident.^[42][48] They currently continue to operate throughout Iraq.

Main article: Organization of the United States Marine Corps

The Department of the Navy, led by the Secretary of the Navy (SECNAV), administers both the Marine Corps and the Navy. The most senior Marine officer is the Commandant of the Marine Corps, responsible for organizing, recruiting, training, and equipping the Marine Corps so that it is ready for operation under the command of the Unified Combatant Commanders. The Marine Corps is organized into four principal subdivisions: Headquarters Marine Corps (HQMC), the Operating Forces, the Supporting Establishment, and the Marine Forces Reserve (MARFORRES or USMCR).

The Operating Forces are further subdivided into three categories: Marine Corps Forces (MARFOR) assigned to unified commands, Marine Corps Security Forces guarding high-risk naval installations, and Marine Corps Security Guard detachments at American embassies. Under the "Forces for Unified Commands" memo, Marine Corps Forces are assigned to each of the regional unified commands at the discretion of the Secretary of Defense and with the approval of the President. Since 1991, the Marine Corps has maintained component headquarters at each of the regional unified combatant commands.^[49] Marine Corps Forces are further divided into Marine Forces Command (MARFORCOM) and Marine Forces Pacific (MARFORPAC), each headed by a Lieutenant General. MARFORCOM has operational control of the II Marine Expeditionary Force; MARFORPAC has operational control of the I Marine Expeditionary Force and III Marine Expeditionary Force.^[19]

The Supporting Establishment includes Marine Corps Combat Development Command (MCCDC), Marine Corps Recruit Depots, Marine Corps Logistics Command, Marine bases and air stations, Recruiting Command, and the Marine Band.

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.^[32]

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".^[50][51] 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.^[15] The Navy's Blue Angels flight demonstration team includes at least one Marine pilot, and is supported by a Marine C-130 Hercules aircraft.^[15] In cities with Navy and Marine Corps presence, social activities are often conducted together, for example with the Navy/Marine ball in San Diego.

Main article: Marine Air-Ground Task Force

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)^[52] 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.^[4]

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 (with the exception of the 31st MEU(SOC) based in Okinawa, which is always forward deployed and spends the majority of time at sea, only rotating out the air and ground units which make up the Aviation Command Element and the Ground Combat Element). Each MEU is rated as capable of performing special operations.^[53]

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.^[54] 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.^[55] 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.^[56]

The Commandant of the Marine Corps is the highest-ranking officer of the Marine Corps, though he may not be the senior officer in time and grade. He is both the symbolic and functional head of the Corps, and holds a position of very high esteem among Marines. The commandant has the U.S. Code Title 10 responsibility to man, train, and equip the Marine Corps. He does not serve as a direct battlefield commander. The Commandant is a member of the Joint Chiefs of Staff, and reports to the Secretary of the Navy.^[57]

The current and 34th Commandant of the Marine Corps is General James T. Conway; his nomination was confirmed by the Senate on August 2, 2006. Conway was then promoted to General, and assumed command as the 34th Commandant of the Marine Corps on November 13, 2006.^[58] As of October 2007, Marine General James E. Cartwright (Vice Chairman of the Joint Chiefs of Staff) is senior in terms of time in grade to the commandant.^[59]

As in the rest of the U.S. military, ranks fall into one of three categories: commissioned officer, warrant officer, and enlisted, in decreasing order of authority. To standardize compensation, each rank is assigned a pay grade. The following tables list the rank, abbreviation, pay grade, and insignia of each rank.^[60]

See also: United States Marine Corps officer rank insignia

Commissioned Officers are distinguished from other officers by their commission, which is the formal written authority, issued in the name of the President of the United States, that confers the rank and authority of a Marine Officer. Commissioned officers carry the "special trust and confidence" of the President of the United States. Commissioned officer ranks are further subdivided into Generals, field-grade officers, and company-grade officers.^[11]

Commissioned Officer Rank Structure of the United States Marine Corps
General Officers
General (Gen)	Lieutenant General (LtGen)	Major General (MajGen)	Brigadier General (BGen)
O-10	O-9	O-8	O-7

Field-grade Officers
Colonel (Col)	Lieutenant Colonel (LtCol)	Major (Maj)
O-6	O-5	O-4
Company-grade Officers
Captain (Capt)	First Lieutenant (1stLt)	Second Lieutenant (2ndLt)
O-3	O-2	O-1

Warrant Officers provide leadership and skills in specialized fields. Unlike most other militaries, the American military confers commissions on its Warrant Officers, though they are generally not responsible for leadership outside of their specialty. Warrant officers come primarily from the senior Non-Commissioned Officer ranks.

A Chief Warrant Officer, CWO2-CWO5, serving in the MOS 0306 "Infantry Weapons Officer" carries a special title, "Marine Gunner" (not a rank). A Marine Gunner replaces the Chief Warrant Officer insignia on the left collar with a bursting bomb insignia. Other warrant officers are sometimes informally also referred to as "Gunner," but this usage is not correct.

Warrant Officer Rank Structure of the United States Marine Corps
Chief Warrant Officer-5 (CWO-5)	Chief Warrant Officer-4 (CWO-4)	Chief Warrant Officer-3 (CWO-3)	Chief Warrant Officer-2 (CWO-2)	Warrant Officer 1 (WO-1) (is being discontinued)
W-5	W-4	W-3	W-2	W-1

See also: United States Marine Corps enlisted rank insignia

Enlisted Marines in the pay grades E-1 to E-3 are not "non-commissioned officers" (NCOs); they make up the bulk of the Corps' ranks. They are also often referred to as "non-NCOS" Although they do not technically hold leadership ranks, the Corps' ethos stresses leadership among all Marines, and junior Marines are often assigned responsibility normally reserved for superiors.

Those in the pay grades of E-4 and E-5 are non-commissioned officers (NCOs). They primarily supervise junior Marines and act as a vital link with the higher command structure, ensuring that orders are carried out correctly. Marines E-6 and higher are Staff Non-Commissioned Officers (SNCOs), charged with supervising NCOs and acting as enlisted advisors to the command.

The E-8 and E-9 levels each have two ranks per pay grade, each with different responsibilities. Gunnery Sergeants (E-7) indicate on their annual evaluations, called "fitness reports", or "fitreps" for short, their preferred promotional track: Master Sergeant or First Sergeant. The First Sergeant and Sergeant Major ranks are command-oriented, with Marines of these ranks serving as the senior enlisted Marines in a unit, charged to assist the commanding officer in matters of discipline, administration and the morale and welfare of the unit. Master Sergeants and Master Gunnery Sergeants provide technical leadership as occupational specialists in their specific MOS. First Sergeants typically serve as the senior enlisted Marine in a company, battery or other unit at similar echelon, while Sergeants Major serve the same role in battalions, squadrons or larger units.

The Sergeant Major of the Marine Corps is a unique rank conferred on the senior enlisted Marine of the entire Marine Corps, personally selected by the Commandant of the Marine Corps. The Sergeant Major of the Marine Corps wears unique chevrons with the Eagle, Globe, and Anchor at the center, flanked by two five-point stars.

Staff Noncommissioned Officer (SNCO) Rank Structure of the United States Marine Corps
Sergeant Major of the Marine Corps (SgtMajMC)	Sergeant Major (SgtMaj)	Master Gunnery Sergeant (MGySgt)	First Sergeant (1stSgt)	Master Sergeant (MSgt)	Gunnery Sergeant (GySgt)	Staff Sergeant (SSgt)
E-9	E-9	E-9	E-8	E-8	E-7	E-6

Noncommissioned Officer (NCO) Rank Structure of the United States Marine Corps
Sergeant (Sgt)	Corporal (Cpl)
E-5	E-4

Enlisted Rank Structure of the United States Marine Corps
Lance Corporal (LCpl)	Private First Class (PFC)	Private (Pvt)
E-3	E-2	E-1
		no insignia

Junior Marines, those not yet non-commissioned officers (Privates, Privates First Class, and Lance Corporals), are typically addressed by their last names. Non-commissioned officers are addressed by rank and last name. All officers, both commissioned and warrant, are addressed as "sir" or "ma'am". Warrant Officers are sometimes informally addressed as "Gunner", although the usage of this term is improper unless the Warrant Officer holds the Military Occupational Specialty of Infantry Weapons Officer (MOS 0306). Addressing an officer by his or her rank is a technically accepted, but rarely used and often frowned upon, form of courtesy. The nautical term "Skipper" is also used when referring to the commanding officer of a specific unit by those who report to him or her, however this is an informal title, the use of which would likely be frowned on in many cases and never used when directly addressing a senior officer.

During recruit training, recruits are not considered full-fledged Marines; as a result, all Marines who have completed recruit training are addressed as "sir" or "ma'am" by incoming recruits who are beginning recruit training. Also, incoming recruits must also refer to themselves in the third persion (I.E. "this recruit"), and their rank is replaced with the word "Recruit". This usually lasts until the last week of recruit training when in most instances, recruits are then considered-full fledged Marines.

Informally, some enlisted ranks have commonly used nicknames, though they are not official and are technically improper. A Gunnery Sergeant is typically called "Gunny" and (much less often) "Guns", a Master Sergeant is commonly called "Top", a First Sergeant is sometimes referred to as "The First Shirt", and a Master Gunnery Sergeant is "Master Guns" or "Master Gunny". Differing from the US Army and Air Force, all ranks containing "Sergeant" are always addressed by their full rank and never shortened to simply "Sergeant" or "Sarge". A Private First Class is usually referred to as a PFC, instead of simply "private" as the Army does.

Finally, Marines generally consider it an insult to be called a "soldier" (as soldiers are in the Army); the proper term is always Marine.^[11]

Every year, over 2000 new Marine officers are commissioned, and 38,000 recruits accepted and trained.^[19] Commissioned officers are commissioned mainly through one of three sources: Naval Reserve Officer Training Corps (NROTC), Officer Candidates School (U.S. Marine Corps) (OCS), or the United States Naval Academy (USNA). All officer candidates are screened and evaluated for fitness to lead Marines; OCS candidates are screened during either two 6-week courses or one 10-week course at OCS. NROTC midshipmen are screened during one 6-week course at OCS and Academy Midshipmen may choose to be screened at a month-long training program called Leatherneck.

Following commissioning, all Marine commissioned officers, regardless of accession route or further training requirements, attend The Basic School (TBS) at Marine Corps Base Quantico, Virginia. There, they spend six months learning to command a rifle platoon. The Basic School, for second lieutenants and warrant officers learning the art of infantry and combined arms warfare, is an example of the Corps' approach to furthering the concept that "Every Marine is a rifleman".^[11]

Main article: United States Marine Corps Boot Camp

Enlisted Marines attend recruit training, known as boot camp, at either Marine Corps Recruit Depot (MCRD) San Diego or Marine Corps Recruit Depot Parris Island, just outside Beaufort, South Carolina. Women only attend the Parris Island depot, in the Fourth Recruit Training Battalion, while males who train at Parris Island comprise the First through Third Battalions. Historically, the Mississippi River served as the dividing line which delineated who would be trained where. More recently the recruiting district system has been implemented, resulting in a more even distribution of male recruits between the two MCRD facilities. All recruits must pass an Initial Strength Test to start training. Recruits who fail to do so are placed in a Physical Conditioning Platoon, where they receive individualized attention and training until the minimum standards are reached.

Marine recruit training is the longest among the American military services; it is 13 weeks long, compared to the U.S. Army's 10 weeks.

Following recruit training, enlisted US Marines then attend School of Infantry training at Camp Geiger or Camp Pendleton, generally based upon where the Marine received their recruit training. Infantry Marines begin their Military Occupational Specialty (MOS) training, which is 52-days long, immediately with the Infantry Training Battalion (ITB). Marines in all other MOSs train for 22 days in Marine Combat Training (MCT), learning common infantry skills, before continuing on to their MOS schools which vary in length.^[61]

Main article: Uniforms of the United States Marine Corps