Of all the U.S. administration escalating U.S. involvement in Vietnam, Kennedy's seems the least "forced." Truman essentially stood aside going with the French flow in his first term. In his second, he just aligned Vietnam policy with shifts in Asian containment after the Korean War started. Eisenhower basically faced an outright choice of letting reunificationelections (which the communists would win) or not. So, a U.S. commitment to South Vietnam before July 1956 was the only alternative to losing the territory. Johnson in 1965 was dealing with an ARVN that was losing people faster than it was replacing its losses, and unbeknownst to him, Hanoi had started sending regular PAVN in. Plus he was dealing with open turmoil and revolving door governments in Saigon.
What was Kennedy dealing with by contrast? A Diem regime, unpopular, but in the saddle. A rising Viet Cong campaign (officially kicked off a few months before he was elected, effectively started a couple years earlier). But no one at the time was suggesting that South Vietnam's demise was imminent. Certainly nobody was saying that Saigon would fall to Reds before the 1962 or 1964 U.S. elections. The VC were gradually taking over the countryside.
So, while there was no situation justifying a reduction of the Eisenhower administration's aid and advisory program, there was no pressure on the ground that really meant JFK needed to multiply the number advisors by a huge factor and encadre them with ARVN combat units in the field, at least not in 1961-1962, when the decision was made. Rather than escalating to avoid an imminent loss, Kennedy, on the advice of Taylor and Rostow, escalated to prove a point and to actively achieve a "win" against a national liberation war.
What if he just didn't? There were plenty of other ways in which JFK got to show Cold War dynamism. Arms buildups, Berlin and Cuba crises, upping the space program and science ed. As long as there is not media-worthy, visible and dramatic deterioration of South Vietnam, right-wing criticism of JFK for failing to do more in Vietnam would not really stick. The thing about proactively instead of reactively increasing the commitment to Vietnam is that you increase the media's focus on the country and its flaws rather than keeping them quiet.
[A note on Kennedy’s assassination. The rest of what I say presumes it still happens at the same time is OTL. While changes in Vietnam possibility could butterfly it away, it is not a direct knock-on. If the variables of a lesser standard of presidential security, a desire to visit Dallas, and a guy who still wants to kill Kennedy are all still President, it could still happen, even if particular details of Kennedy’s and Oswald’s days up to that points are different. So it really just becomes a matter of preference. One could also try to speculate on later events with Kennedy alive through the 1960s]
So - how do things work out in Vietnam in '62 and '63 if the US advisory contingent is smaller and still training, but not fighting? The US could at the same time be upping military aid if Diem is requesting it. Are the VC going to be making gains at such a rate that Kennedy will have to start having advisors do combat, only a year later than OTL?
If he is able to avoid escalation until November '63, will this reduce the spotlight on Diem's flaws, and prevent a U.S. endorsed coup against Diem? If so that should have further knock-on effects of slowing escalatory pressures for at least the first year or so of the Johnson Administration, there might not be a U.S ground troop deployment until after the 1966 midterms, if that early. In any case, Johnson opposed the coup against Diem, so it could take a lot to bring him around to support it if it hasn’t happened before he becomes President.
Also, in the meantime, other things may first grab JFK or LBJ’s attention. For instance, in September 1963 the “Konfrontasi” is heating up in Malaysian Borneo, and between that point and September 1965, Sukarno is becoming increasingly anti-UN and tied to Mao. Maybe the U.S. would be concerned about potentially Maoist aligned rebels gaining power over the oil and straits of this region and would want to help the British. Or, from 63 or 64, the U.S., less mono-focused on Vietnam, could get more concerned with the deteriorating British position in Aden.
What was Kennedy dealing with by contrast? A Diem regime, unpopular, but in the saddle. A rising Viet Cong campaign (officially kicked off a few months before he was elected, effectively started a couple years earlier). But no one at the time was suggesting that South Vietnam's demise was imminent. Certainly nobody was saying that Saigon would fall to Reds before the 1962 or 1964 U.S. elections. The VC were gradually taking over the countryside.
So, while there was no situation justifying a reduction of the Eisenhower administration's aid and advisory program, there was no pressure on the ground that really meant JFK needed to multiply the number advisors by a huge factor and encadre them with ARVN combat units in the field, at least not in 1961-1962, when the decision was made. Rather than escalating to avoid an imminent loss, Kennedy, on the advice of Taylor and Rostow, escalated to prove a point and to actively achieve a "win" against a national liberation war.
What if he just didn't? There were plenty of other ways in which JFK got to show Cold War dynamism. Arms buildups, Berlin and Cuba crises, upping the space program and science ed. As long as there is not media-worthy, visible and dramatic deterioration of South Vietnam, right-wing criticism of JFK for failing to do more in Vietnam would not really stick. The thing about proactively instead of reactively increasing the commitment to Vietnam is that you increase the media's focus on the country and its flaws rather than keeping them quiet.
[A note on Kennedy’s assassination. The rest of what I say presumes it still happens at the same time is OTL. While changes in Vietnam possibility could butterfly it away, it is not a direct knock-on. If the variables of a lesser standard of presidential security, a desire to visit Dallas, and a guy who still wants to kill Kennedy are all still President, it could still happen, even if particular details of Kennedy’s and Oswald’s days up to that points are different. So it really just becomes a matter of preference. One could also try to speculate on later events with Kennedy alive through the 1960s]
So - how do things work out in Vietnam in '62 and '63 if the US advisory contingent is smaller and still training, but not fighting? The US could at the same time be upping military aid if Diem is requesting it. Are the VC going to be making gains at such a rate that Kennedy will have to start having advisors do combat, only a year later than OTL?
If he is able to avoid escalation until November '63, will this reduce the spotlight on Diem's flaws, and prevent a U.S. endorsed coup against Diem? If so that should have further knock-on effects of slowing escalatory pressures for at least the first year or so of the Johnson Administration, there might not be a U.S ground troop deployment until after the 1966 midterms, if that early. In any case, Johnson opposed the coup against Diem, so it could take a lot to bring him around to support it if it hasn’t happened before he becomes President.
Also, in the meantime, other things may first grab JFK or LBJ’s attention. For instance, in September 1963 the “Konfrontasi” is heating up in Malaysian Borneo, and between that point and September 1965, Sukarno is becoming increasingly anti-UN and tied to Mao. Maybe the U.S. would be concerned about potentially Maoist aligned rebels gaining power over the oil and straits of this region and would want to help the British. Or, from 63 or 64, the U.S., less mono-focused on Vietnam, could get more concerned with the deteriorating British position in Aden.