United States Marine Corps

==Mission==
As outlined in {{USC|10|5063}} and as originally introduced under the [[National Security Act of 1947]], three primary areas of responsibility for the U.S. Marine Corps are:
* Seizure or defense of advanced naval bases and other land operations to support [[naval warfare|naval campaigns]];
* Development of tactics, technique, and equipment used by amphibious landing forces in coordination with the [[United States Army|Army]] and [[United States Air Force|Air Force]]; and
* Such other duties as the [[President of the United States|President]] or [[United States Department of Defense|Department of Defense]] may direct.
This last clause derives from similar language in the [[United States Congress|Congressional]] acts ''"For the Better Organization of the Marine Corps"'' of 1834, and ''"Establishing and Organizing a Marine Corps"'' of 1798. In 1951, the [[United States House of Representatives|House of Representatives']] [[United States House Committee on Armed Services|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 [[First Barbary War|Tripoli]], the [[War of 1812]], [[Battle of Chapultepec|Chapultepec]], and numerous [[counterinsurgency]] and occupational duties (such as those in Central America, [[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.<ref name="Estes">{{Cite book|last=Estes|first=Kenneth W.|title=The Marine Officer's Guide, 6th Edition|publisher=Naval Institute Press|year=2000|isbn=1-55750-567-5}}</ref>

The [[United States Marine Band|Marine Band]], dubbed the "President's Own" by [[Thomas Jefferson]], provides music for state functions at the [[White House]].<ref>{{cite book |title=Public Papers of the Presidents of the United States, William J. Clinton, 1998, Book 2: July 1 to December 31, 1998 |first=William J. |last=Clinton |editor=Office of the Federal Register |author-link=Bill Clinton |page=[https://archive.org/details/unitedstatesmari0000lurc/page/1217 1217] |publisher=Government Printing Office |year=2000 |isbn=978-1-4034-4551-3 |chapter=Remarks Celebrating the 200th Anniversary of the United States Marine Corps Band 10 July 1998 |quote=The Marine Band played at Thomas Jefferson's Inauguration in 1801 and hasn't missed a single one since. Jefferson was a violin player who loved music almost as much as he loved freedom. He named the band "The President's Own". |chapter-url=https://archive.org/details/unitedstatesmari0000lurc/page/1217}}</ref> Marines from Ceremonial Companies A & B, quartered in [[Marine Barracks, Washington, D.C.]], guard presidential retreats, including [[Camp David]], and the Marines of the Executive Flight Detachment of [[HMX-1]] provide helicopter transport to the President and [[Vice President of the United States|Vice President]], with the radio call signs "[[Marine One]]" and "Marine Two", respectively.<ref>{{cite book|title=Marines: An Illustrated History: The United States Marine Corps from 1775 to the 21st Century| first=Chester G.|last= Hearn|page=180|publisher= Zenith Imprint|year= 2007 |isbn= 978-0-7603-3211-5}}</ref> The Executive Flight Detachment also provides helicopter transport to [[United States Cabinet|Cabinet members]] and other [[Very important person|VIPs]]. By authority of the 1946 Foreign Service Act, the [[Marine Security Guard]]s of the Marine Embassy Security Command provide security for American [[diplomatic mission|embassies]], [[legation]]s, and [[Consul (representative)|consulates]] at more than 140 posts worldwide.<ref>{{cite book|title=Marine Pride: A Salute to America's Elite Fighting Force |url=https://archive.org/details/marinepridesalut0000kell |url-access=registration |first= Scott |last=Keller |page=[https://archive.org/details/marinepridesalut0000kell/page/56 56]|publisher= Citadel Press|year=2004 |isbn =978-0-8065-2603-4}}</ref>

The relationship between the [[United States Department of State|Department of State]] and the U.S. Marine Corps is nearly as old as the Corps itself. For over 200 years, Marines have served at the request of various [[United States Secretary of State|Secretaries of State]]. After [[World War II]], an alert, disciplined force was needed to protect American embassies, consulates, and legations throughout the world. In 1947, a proposal was made that the Department of Defense furnishes Marine Corps personnel for Foreign Service guard duty under the provisions of the Foreign Service Act of 1946. A formal Memorandum of Agreement was signed between the Department of State and the [[United States Secretary of the Navy|Secretary of the Navy]] on 15 December 1948, and 83 Marines were deployed to overseas missions. During the first year of the program, 36 detachments were deployed worldwide.<ref>{{cite web|url=http://2001-2009.state.gov/m/ds/rls/33081.htm|title=The Role of Marines in Embassy Security|access-date=22 November 2015|archive-url=https://web.archive.org/web/20160304094058/http://2001-2009.state.gov/m/ds/rls/33081.htm|archive-date=4 March 2016|url-status=live}}</ref>

===Historical mission===
The Marine Corps was founded to serve as an infantry unit aboard naval vessels and was responsible for the security of the ship and its crew by conducting offensive and defensive combat during [[Naval boarding|boarding actions]] and defending the ship's officers from [[mutiny]]; to the latter end, their quarters on the ship were often strategically positioned between the officers' quarters and the rest of the vessel. Continental Marines manned raiding parties, both at sea and ashore. America's first amphibious assault landing occurred early in the [[American Revolutionary War|Revolutionary War]] on 3 March 1776 as the Marines gained control of [[Fort Montagu]] and [[Old Fort of Nassau|Fort Nassau]], a [[British Empire|British]] ammunition depot and naval port in [[New Providence]], the Bahamas. The role of the Marine Corps has expanded significantly since then; 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 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. In 1987 the USMC Sea School was closed; in 1998 all Marine Detachments on board ships were disbanded. 

Throughout the late 19th and 20th centuries, Marine detachments served aboard Navy cruisers, battleships, and aircraft carriers. Marine detachments served in their traditional duties as a ship's landing force, manning the ship's weapons and providing shipboard security. Marine detachments were augmented by members of the ship's company for landing parties, such as in the [[First Sumatran expedition]] of 1832 and continuing in the Caribbean and [[United States occupation of Veracruz|Mexican campaign]]s of the early 20th centuries. Marines developed tactics and techniques of amphibious assault on defended coastlines in time for use in World War II.<ref name="Lawliss">{{Cite book |last= Lawliss |first= Chuck |title= The Marine Book: A Portrait of America's Military Elite |publisher= Thames and Hudson |year= 1988 |location= New York}}</ref> During World War II, Marines continued to serve on capital ships, and some were assigned to man anti-aircraft batteries.<ref>{{Cite book |last=Hough, LtCol. |first=Frank O. |url=https://www.usmcu.edu/Portals/218/History%20of%20the%20U.S.%20Marine%20Corps%20in%20WWII%20Vol%20I%20-%20Pearl%20Harbor%20to%20Guadacanal%20%20PCN%2019000262400.pdf |title=Pearl Harbor to Guadalcanal: History of U.S. Marine Corps Operations in World War II |last2=Ludwig |first2=Verle E. |last3=Shaw, Jr. |first3=Henry I. |publisher=Historical Branch, G-3 Division, Headquarters, U.S. Marine Corps |year=1989 |volume=1 |language=en |lccn=58-60002 |archive-url=https://archive.org/details/historyofusmarin01usma/page/n3/mode/2up |archive-date=2013-06-25}}</ref>

In 1950,<ref>{{Cite web|url=https://www.marines.mil/Portals/1/Publications/A%20Chronology%20of%20the%20United%20States%20Marine%20Corps%201947-1964%20%20PCN%2019000318200.pdf|title=A Chronology of the United States Marine Corps Historical Reference Pamphlet|date=1947–1964|website=Marines.mil|access-date=29 April 2020|archive-date=5 June 2020|archive-url=https://web.archive.org/web/20200605151639/https://www.marines.mil/Portals/1/Publications/A%20Chronology%20of%20the%20United%20States%20Marine%20Corps%201947-1964%20%20PCN%2019000318200.pdf|url-status=live}}</ref> President [[Harry S. Truman|Harry Truman]] responded to a message from U.S. Representative [[Gordon L. McDonough]]. McDonough had urged President Truman to add Marine representation on the [[Joint Chiefs of Staff]]. President Truman, writing in a letter addressed to McDonough, stated that "The Marine Corps is the Navy's police force and as long as I am President that is what it will remain. They have a propaganda machine that is almost equal to [[Joseph Stalin|Stalin's]]." McDonough then inserted [https://commons.m.wikimedia.org/wiki/File:Letter,_Harry_Truman_to_Gordon_McDonough,_29_August_1950_(15310975758).jpg President Truman's letter], dated 29 August 1950, into the ''[[Congressional Record]]''. Congressmen and Marine organizations reacted, calling President Truman's remarks an insult and demanded an apology. Truman apologized to the Marine commandant at the time, writing, "I sincerely regret the unfortunate choice of language which I used in my letter of August 29 to Congressman McDonough concerning the Marine Corps." While Truman had apologized for his metaphor, he did not alter his position that the Marine Corps should continue to report to the Navy secretary. He made amends only by making a surprise visit to the [[Marine Corps League]] a few days later, when he reiterated, "When I make a mistake, I try to correct it. I try to make as few as possible." He received a standing ovation.<ref>{{Cite news|last=Battistella|first=Edwin|url=https://www.politico.com/magazine/story/2014/05/the-art-of-the-political-apology-106458/|title=The Art of the Political Apology|date=7 May 2014|work=Politico.com|access-date=14 January 2024|archive-date=20 October 2020|archive-url=https://web.archive.org/web/20201020070506/https://www.politico.com/magazine/story/2014/05/the-art-of-the-political-apology-106458_Page2.html|url-status=live}}</ref>

When gun cruisers were retired by the end of the 1970s, the remaining Marine detachments were only seen on battleships and carriers. Its original mission of providing shipboard security ended in the 1990s.<ref>{{Cite web |title=The Corps' Salty Seadogs Have All But Come Ashore: Seagoing Traditions Founder as New Millennium Approaches |url=http://public2.nhhcaws.local/research/library/online-reading-room/title-list-alphabetically/c/the-corps-salty-seadogs-have-all-but-come-ashore-seagoing-traditions-founder-as-new-millennium-approaches.html |access-date=2023-12-16 |website=public2.nhhcaws.local |language=en-US}}</ref>

===Capabilities===
The Marine Corps fulfills a critical military role as an amphibious warfare force. It is capable of [[asymmetric warfare]] with [[conventional warfare|conventional]], [[irregular warfare|irregular]], and [[hybrid warfare|hybrid forces]]. While the Marine Corps does not employ any unique capabilities, as a force it can 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 element]], an [[aviation combat element]] and a [[logistics combat element]] under a common [[Command element (United States Marine Corps)|command element]]. While the creation of joint commands under the [[Goldwater–Nichols Act]] has improved interservice coordination between each branch, the Corps's ability to permanently maintain integrated multielement task forces under a single command provides a smoother implementation of combined-arms warfare principles.<ref name="Warren">{{Cite book |last= Warren |first= James A. |title= American Spartans: The U.S. Marines: A Combat History From Iwo Jima to Iraq |publisher= Free Press, Simon & Schuster |year= 2005 |location= New York |isbn= 0-684-87284-6 |url= https://archive.org/details/americanspartans00warr}}</ref>

[[File:Marine-31st.jpg|thumb|U.S. Marines from the [[31st Marine Expeditionary Unit]] training ]]
The close integration of disparate Marine units stems from an organizational culture centered on 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, [[United States Marine Corps Aviation|Marine aviation]] has always been focused on [[close air support]] and has remained largely uninfluenced by air power theories proclaiming that [[strategic bombing]] can single-handedly win wars.<ref name="Lawliss" />

{{anchor|Every Marine is a rifleman}}This focus on the infantry is matched with the doctrine of "Every Marine [is] a rifleman", a precept of Commandant [[Alfred M. Gray, Jr.]], emphasizing the infantry combat abilities of every Marine. All Marines, regardless of [[List of United States Marine Corps MOS|military specialization]], receive training as a [[rifleman]]; and all officers receive additional training as infantry platoon commanders.<ref>{{Cite book |last= Milks |first= Keith A. |title= Ensuring 'Every Marine a Rifleman' is more than just a catch phrase|publisher= 22 MEU, USMC |date= 8 May 2003 |url= http://www.usmc.mil/marinelink/mcn2000.nsf/0/b5ac3322e236c38985256feb00492f93?OpenDocument |archive-url= https://web.archive.org/web/20071224075658/http://www.usmc.mil/marinelink/mcn2000.nsf/0/b5ac3322e236c38985256feb00492f93?OpenDocument |archive-date=24 December 2007 |id= Story ID # 20071230234422}}</ref> During World War II at the [[Battle of Wake Island]], when all of the Marine aircraft were destroyed, pilots continued the fight as ground officers, leading supply clerks and cooks in a final defensive effort.<ref name="Heinl">{{Cite web |author= R.D. Heinl, Jr |title= Marines in WWII Historical Monograph: The Defense of Wake |publisher= Historical Section, Division of Public Information, Headquarters, USMC |year= 1947 |url= http://www.ibiblio.org/hyperwar/USMC/USMC-M-Wake.html |access-date= 28 August 2006 |archive-url= https://web.archive.org/web/20061002174813/http://www.ibiblio.org/hyperwar/USMC/USMC-M-Wake.html |archive-date= 2 October 2006|df= dmy-all}}</ref> Flexibility of execution is implemented via an emphasis on "[[Intent (military)|commander's intent]]" as a guiding principle for carrying out orders, specifying the end state but leaving open the method of execution.<ref name="Lind">{{Cite book |last1= Lind |first1= William S. |author-link= William S. Lind |first2=Michael|last2=Wyly |author-link2=Michael Wyly |title= Maneuver Warfare Handbook |publisher=Westview Press |year= 1985 |location=Boulder, Colorado |isbn= 0-86531-862-X}}</ref>

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.<ref name="OMFTS"/> 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. In light of recent warfare that has strayed from the Corps's traditional missions,<ref name="2ndarmy"/> the Marines have renewed an emphasis on amphibious capabilities.<ref>{{cite web|url=http://www.marines.mil/unit/iimef/Pages/Amphibiousroots.aspx|title=Marines return to their amphibious roots|last=Patrick|first=Capt Timothy|date=10 December 2010|work=[[II Marine Expeditionary Force]]|publisher=United States Marine Corps|access-date=22 December 2010|archive-url=https://web.archive.org/web/20101225055336/http://www.marines.mil/unit/iimef/Pages/Amphibiousroots.aspx|archive-date=25 December 2010|url-status=live}}</ref>

[[File:USS Tarawa operations.jpg|thumb|Marines from the 15th Marine Expeditionary Unit depart {{USS|Tarawa|LHA-1}}, using both a Landing Craft Utility and CH-53E "Super Stallion" helicopters, during amphibious operations in Kuwait, 2003.]]
The Marine Corps relies on the Navy for [[sealift]] to provide its rapid deployment capabilities. In addition to basing a third of the [[Fleet Marine Force]] in Japan, [[Marine expeditionary unit]]s (MEU) are typically stationed at sea so they can function as first responders to international incidents.<ref name="ChenowethNihart">{{Cite book|last1= Chenoweth|first1= H. Avery|last2= Nihart|first2= Brooke|title= Semper fi: The Definitive Illustrated History of the U.S. Marines|publisher= Main Street|year= 2005|location= New York|isbn= 1-4027-3099-3}}</ref> To aid rapid deployment, the [[Military Sealift Command|Maritime Pre-Positioning System]] was developed: fleets of [[container ship]]s are positioned throughout the world with enough equipment and supplies for a [[marine expeditionary force]] to deploy for 30 days.{{Citation needed|date=March 2021}}

===Doctrine===
Two small manuals published during the 1930s established USMC doctrine in two areas. The ''[[Small Wars Manual]]'' laid the framework for Marine [[counter-insurgency]] operations from [[Vietnam War|Vietnam]] to [[Iraq War|Iraq]] and [[War in Afghanistan (2001–2021)|Afghanistan]] while the ''Tentative Landing Operations Manual'' established the doctrine for the [[United States amphibious operations|amphibious operations of World War II]]. "''Operational Maneuver from the Sea''" was the doctrine of power projection in 2006.<ref name="OMFTS"/>