No, he wasn't.
General Westmoreland was commander of US forces in South Vietnam during LBJs administration.
..."I shall not seek, and I will not accept, the nomination of my party for another term as your President" - Lyndon B. Johnson, March 31, 1968The 36th President of the United States was Lyndon B. Johnson did not run for President in 1968. Johnson was in office from November 22, 1963 when he succeeded Kennedy after the assassination, and was reelected in 1964 to serve a second term until January 20, 1969. The candidates for the Presidential election of 1968 were; Democrats Hubert Humphrey - Edmund Muskie Republicans Richard Nixon - Spiro Agnew, and American Independents George Wallace - Curtis LeMay. Richard Nixon won the election to be come the 37th President of the United States. President Nixon was reelected in 1972, and was in office from January 20, 1969 until August 9, 1974 when he was impeached.
NVA Gen. Giap was the supreme commander.
General William Westmoreland was .
Ngo Dinh Diem was the leader of South Vietnam until he was assassinated in November of 1963
Northern army.
The campaign for the US Presidency in 1964 was between Democrat President Lyndon Johnson and Republican candidate Senator Barry Goldwater. Although the South had been traditionally a Democrat stronghold for decades after the US Civil War, it also had a large part of the voting population leaning to the conservative side of American politics. To many Southerners, the conservatism of Barry Goldwater seemed more in line with their ideas than did the more liberal President Johnson. So even though Johnson was a Texan, he did not command the full support of some Southern States who voted for the more conservative Goldwater.
After US President Lyndon Johnson's easy victory in the 1964 US presidential election over Barry Goldwater, LBJ had received America's endorsement. As for Vietnam, the way to improve anti-Communist prospects in South Vietnam,was to use the lever of air strikes against North Vietnam. This would pressure Saigon leaders to achieve political stability, improve its army and suppress the Buddhist monks and get rid of incompetent officials.
NVA Gen. Giap was the supreme commander.
In April 1975, it was strictly a North-South War; NVA vs ARVN (North Viet Army vs Army Republic (South) Vietnam). The ARVN, what was left of it, surrendered to the NVA commander(s) 30 April 1975. Although it should be pointed out, that when the ARVN commander walked out to meet the NVA commander who had just smashed his T54 medium tanks thru the South Vietnamese Capital's Palace gates...and offered to surrender his forces, the NVA commander replied, "...General...you have no forces left to surrender!"
Although Vietnam was part of the lives of presidents Eisenhower & Kennedy, the war dominated the lives of Commander in Chief's LBJ & Nixon. Watergate effectively eliminated Nixon from the position of C & C (Commander in Chief), and when he left office (resigned) there was NO ONE remaining to defend South Vietnam...and Congress immediately went after the Vietnam War...by completely cutting off any further funding to South Vietnam...with no shells for their artillery, no fuel for their tanks, and other accouterments of war, the south quickly fell to the northern invaders.
The Republic of South Vietnam SURRENDERED to the North Vietnamese Army on April 30, 1975; when NVA Tanks crashed through the South Vietnamese Capital's gates. Although, when the South Viet Commander met the NVA commander and stated that he wished to surrender his forces to him, the NVA commander stated, "...you have no forces left to surrender!"