More than a year since the start of the Tết Offensive, President Nixon authorised Operation Menu (previously intended as Operation Breakfast) allowing for a concentrated period of intense bombing in Cambodia along its southeast border with Vietnam. Technically, bombing in Cambodia had begun under President Johnson in 1965 after the initiation of Operation Rolling Thunder. However, under President Johnson, the bombing in Cambodia was seen as a spillover of the fighting against the People’s Army of Vietnam (PAVN) and the National Liberation Front (NLF). Conversely, Operation Menu authorised by President Nixon on 15 March 1969 was a direct order to bomb inside Cambodian territory.
In the infographic timelapse below, created for the exhibit Remembering Vietnam: Twelve Critical Episodes in the Vietnam War on 6 January 2019 at the National Archives Museum in Washington DC, the extent of American bombings all over Vietnam as a well as inside Cambodia and Laos can be seen. It shows all bombing runs from 1965 to 1973 (highlighted by red dots) and which areas were most affected by them (highlighted in green). It is obvious that US B-52s had targeted northern and southern parts of Laos from as early as 1965, no doubt in an effort to disrupt the crucial Democratic Republic of Vietnam (DRV) supply lines running through Laos along the Ho Chi Minh Trail.
Until US and Army of the Republic of Vietnam (ARVN) forces could successfully interdict the Ho Chi Minh Trail, they would fight the war with what felt like one hand tied behind their backs. To combat this handicap, B-52 bombers on standard bombing runs in South Vietnam were redirected to the border with Cambodia on 18 March 1969. As well as aimed at disrupting NLF supply routes and destroying communist sanctuaries along the border, the main target for American bombs was the Central Office for South Vietnam (COSVN), a huge area in the Memot plantation near the Fish Hook area of the border that was used as the resistance headquarters, charged with planning, implementing and directing resistance operations and troops. It was an immensely important target, however, it was never captured or destroyed.
What looked like a decision by President Nixon to expand the war into Cambodia seriously galvanised the American public at home. Anti-war protesters saw the decision as running counter to President Nixon’s promise of bringing the war to an end. This eventually fuelled en masse protests across the nation, including the tragedy at Kent State University where four students were shot and killed by National Guardsmen in 1970.