United States Marine Corps

===Vietnam War===
[[File:U.S. Marines in Operation Allen Brook (Vietnam War) 001.jpg|thumb|U.S. marines of "G" Company, [[2nd Battalion, 7th Marines]] in action during [[Operation Allen Brook]] in South Vietnam, 1968]]

The Marine Corps served in the [[Vietnam War]], taking part in such battles as the [[Battle of Huế|Battle of Hue]] and the [[Battle of Khe Sanh]] in 1968. Individuals from the USMC generally operated in the Northern I Corps Regions of [[South Vietnam]]. While there, they were constantly engaged in a guerrilla war against the [[Viet Cong]], along with an intermittent conventional war against the [[People's Army of Vietnam|North Vietnamese Army]], this made the Marine Corps known throughout Vietnam and gained a frightening reputation from the Viet Cong. Portions of the Corps were responsible for the less-known [[Combined Action Program]] that implemented unconventional techniques for counterinsurgency and worked as military advisors to the [[Republic of Vietnam Marine Division|Republic of Vietnam Marine Corps]]. Marines were withdrawn in 1971 and returned briefly in 1975 to evacuate [[Ho Chi Minh City|Saigon]] and attempt a rescue of the crew of the [[Mayaguez incident|SS ''Mayaguez'']].<ref name="Millet">{{Cite book |last= Millet |first= Alan R. |title= Semper Fidelis: The History of the United States Marine Corps |publisher= Simon & Schuster |year= 1991 |location= New York |page=605 |isbn=978-0-02-921596-8}}</ref> Vietnam was the longest war up to that time for the Marines; by its end, 13,091 had been killed in action,<ref>[http://www.history.navy.mil/faqs/faq56-1.htm Casualties: U.S. Navy and Marine Corps] {{webarchive|url=https://web.archive.org/web/20070605234857/http://www.history.navy.mil/faqs/faq56-1.htm |date= 5 June 2007}}, United States Navy.</ref><ref name="CasualtiesTheWall">Official Navy figures number the marine deaths at 13,091. This source provides a number of 14,837. {{cite web |url=http://www.thewall-usa.com/summary.asp |date=31 March 1997 |title=U.S. Military Casualties in Southeast Asia |publisher=The Wall-USA |url-status=dead |archive-url=https://web.archive.org/web/20060902063652/http://thewall-usa.com/summary.asp |archive-date=2 September 2006}}</ref> 51,392 had been wounded, and 57 Medals of Honor had been awarded.<ref name="CasualtiesUSN">{{cite web|url=http://www.history.navy.mil/faqs/faq56-1.htm |title=Casualties: U.S. Navy and Marine Corps Personnel Killed and Wounded in Wars, Conflicts, Terrorist Acts, and Other Hostile Incidents |date=7 August 2006 |publisher=Naval Historical Center, Department of the Navy |url-status=dead |archive-url=https://web.archive.org/web/20070605234857/http://www.history.navy.mil/faqs/faq56-1.htm |archive-date= 5 June 2007}}</ref><ref name="USMC-MOH">{{cite web|url=http://hqinet001.hqmc.usmc.mil/HD/Historical/Frequently_Requested/Medal_of_Honor.htm|archive-url=https://web.archive.org/web/20070806030250/http://hqinet001.hqmc.usmc.mil/HD/Historical/Frequently_Requested/Medal_of_Honor.htm|archive-date=6 August 2007 |title= Marines Awarded the Medal of Honor |publisher=United States Marine Corps}}</ref> Because of policies concerning rotation, more marines were deployed for service during Vietnam than World War II.<ref>Simmons, 247.</ref>

While recovering from Vietnam, the Corps hit a detrimental low point in its service history caused by [[court-martial|courts-martial]] and non-judicial punishments related partially to increased [[desertion|unauthorized absences and desertions]] during the war. Overhaul of the Corps began in the late 1970s, discharging the most delinquent, and once the quality of new recruits improved, the Corps focused on reforming the non-commissioned officer Corps, a vital functioning part of its forces.<ref name="Warren" />