The two biggest nuggets I've gleaned from this so far:
1. Ho Chi Minh was simply a man who worked tirelessly to free his country and achieve independence. He took military aid from China and Russia because they offered it, not because he viewed Communism as an option. This, to me, was a singularly critical factor in our decision to send troops. The entire exercise was a revolt against colonialism, and then corrupt and incompetent government exacerbated it.
2. By 1954 the United States had already spent one billion dollars (yes, that's correct - a billiion) aiding the Vietnamese in their struggle against both French and British tyranny. This was before a single American soldier's feet touched SE Asian soil. (I'm not counting military advisers as soldiers.)
(1.) This is true throughout the world -- communism ironically never developed in the modern, industrial states as Marx predicted, but always had a strong element of nationalism (a vestigial and antiquated mindset for communists, according to Marx) and anti-colonialism within it. Even the peasant societies of Russia and China were essentially colonial or feudal in their nature, not the industrialized Britain, France, or Germany of the era.
Our inability to read this difference -- between communism, nationalism, and anti-colonialism -- led us down a lot of rabbit holes in the Cold War. You could have argued they were worth it, because if we did not, the Soviets or the Chinese might have done it instead, but sometimes it definitely went too far, and Vietnam is the obvious example of it.
(2.) According to this...
https://thevietnamwar.info/how-much-vietnam-war-cost/
The U.S. spent around $1 trillion (2017 dollars) on the Vietnam conflict. That is actually roughly a third of the Iraq War, so we have that going for us.
The population of Vietnam in 1960 was about 35 million.
Therefore, we could have just given every Vietnamese person about $28,000 and be done with it. South Vietnam's population was about 40% of the total, so mark that number up to $72,000 if you just wanted to hand the south the money.