My Dad served in Vietnam also, as an advisor to a Vietnamese Army Infantry Battalion, right in the middle of Tet. That's him, 2nd from right, after his first combat engagement. Note sergeant first class in center holding AK-47. Generally a sign of NVA or VC Main Force opposition, not local guerillas.
View attachment 99277
Most of his comments about advising ARVN (Army of the Republic of Vietnam) units could easily be applied to our later efforts in Iraq and Afghanistan. The biggest similarity was that we half-assed all three efforts. We dumped a lot of money into equipment without building sustainment capability, we formed large units of troops without the institutions to support them, and we cobbled together advisory teams as a low priority effort. When I told him we were building advisory teams in Iraq, the first words out of his mouth were "I hope they do a better job than we did."
We were never going to win in Vietnam, because the outcome was much more important to the other side than it was to us. They were always going to be willing to fight harder and longer and sacrifice more than we were. Sadly we lost a whole lot of good men learning that lesson, including my Dad, who died last fall of Parkinsons caused by Agent Orange exposure.
That does not mean the cause was wrong. Global communism was not an imagined threat, it was real and it was an existential threat to Western Democracy. Just like Global Islamic Fundamentalism is a threat to us now. But if you cannot figure out a viable method to achieve your goals with the resources at hand, then you have to adjust your goals or you will squander your resources. In war those resources are young mens' lives.
I guess I have to question exactly what the cause 'was.' Certainly, JFK and Robert McNamara sold the war on the basis of fighting expansive communism, but I don't think any of their predecessors believed that.
Ho Chi Minh wanted two things in life - eradicate the French, and he wanted to unify the South Vietnamese people with the North Vietnamese people, who, culturally, had been distant for many generations prior to the French occupation, and are still divided to this day. Ho Chi Minh did not espouse communism as an end, but as a means to bring a people together to fight a common enemy.
In 1941, Ho Chi Minh returned to Vietnam after a long hiatus, and formed the Viet Minh, who were a group of North Vietnamese that resisted the Japanese occupation during WWII. After the end of WWII, he expected that he would have an opening to take power after the Japanese left. Instead, the Japanese honored the agreement they had with the French to return power to them once the war was over, in exchange for them standing aside during the war.
In 1946 after the war ended, Ho Chi Minh appealed to the US to remove the French. But, of course, saying to the United States, 'Hey, US, we want your help in removing your own ally from power in Vietnam and by the way we want to replace them with a communist form of government' was a pretty hard sell. So, they went to war with the French, seizing Hanoi, and in 1954, defeated the French at Bien Din Phu. Treaties were drawn, and the countries were separated in to two countries, North Vietnam and South Vietnam. The French were allowed to stay in Southern Vietnam, but they saw the handwriting on the wall and left.
There was a power vacuum. Eisenhower decided that the US needed to get involved to help the South Vietnamese set up a form of government. But, the decision had been made not to get militarily involved with Vietnam, even though it was known that Ho Chi Minh eventually wanted to retake it.
Fast forward to 1963. The Soviet Union immediately went to work arming the North Vietnamese with a strong military, based on the core Viet Minh, who had endured the Japanese and the French since 1954. Well the Chinese initially but they bailed out pretty quick. So at the end of those ten years, the North Vietnamese had a strong presence.
When the North Vietnamese proceeded to move south past the 17th parallel, JFK, being in an election year, decided that he couldn't have a communist takeover on his watch, so he reversed the policy, and launched the war. The thing about it was, the North Vietnamese had a ten year head start. They had everything. Tanks. Artillery. Heavy mech Infantry. Everything a ground force needed and more of it. We were playing catch up, and the fact that we had to deal with the Viet Cong, insurgent guerillas with no real teeth but a huge nuisance factor, added to the problem. Sure, more troops would have worked. But how many more? We were an army of occupation. That means committing a lot more resources than the insurgent army.
Why did we do it? You can blame it on JFK's election crisis. But, the reality of the situation was, we did form an alliance with the South Vietnamese people and helped form their government. So, I will call it a just cause, but for a different reason than you might.