Editing Robert McNamara (section)

====Background====
The [[Harry S. Truman|Truman]] and [[Dwight D. Eisenhower|Eisenhower]] administrations had committed the U.S. to support the French and native anti-Communist forces in Vietnam in resisting efforts by the Communists in the North to unify the country. Aid was initially limited to financial support, military advice and covert intelligence gathering but expanded after 1954 when the French withdrew. The US [[Military Assistance Advisory Group]] (MAAG) Vietnam was established on 1 November 1955.{{sfn|Lawrence|2009}} In December 1956 the North Vietnam government authorized [[Viet Cong]] forces in South Vietnam to begin a low-level insurgency.{{sfn|Olson|Roberts|2008|p=67}} The Pentagon Papers stated: “All evidence points to fall 1959 as the period in which the Viet Cong made their transition from a clandestine political movement to a more overt military operation...[b]y autumn 1959, however, the VC were in a position to field units of battalion size against regular army formations.”{{sfn|Gelb|2011|p=22-23}}

During President John F. Kennedy's term, American troops in South Vietnam increased from 900 to 16,000 advisers,.<ref name="Vietnam War">{{cite web|url=http://www.swarthmore.edu/library/peace/conscientiousobjection/OverviewVietnamWar.htm|title=Vietnam War|website=swarthmore.edu|publisher=Swarthmore College Peace Collection|access-date=2010-12-20|archive-url=https://web.archive.org/web/20160803124531/http://www.swarthmore.edu/library/peace/conscientiousobjection/OverviewVietnamWar.htm|archive-date=2016-08-03|url-status=dead}}</ref> They were not supposed to engage in combat but rather to train the [[Army of the Republic of Vietnam]] (ARVN).{{sfn|MacKenzie|1997}}{{page needed|date=November 2022}} McNamara was closely aligned with Dean Rusk, the Secretary of State, with both favoring greater American support for South Vietnam.{{sfn|Karnow|1983|p=249}}

The [[#Gulf of Tonkin incident|Gulf of Tonkin incidents]] in August 1964, which involved two purported attacks on U.S. Navy destroyers by North Vietnamese naval vessels, led to an [[#Escalation|escalation]] of U.S. involvement in Vietnam.<ref name="autogenerated2">{{cite web|url=https://fas.org/irp/nsa/spartans/chapter5.pdf|title=Hanyok article|page=177|access-date=October 27, 2015|archive-date=September 25, 2015|archive-url=https://web.archive.org/web/20150925114246/http://fas.org/irp/nsa/spartans/chapter5.pdf|url-status=live}}</ref>