A lot to digest here.
Regarding Ras, I agree with a lot of his points but he is poor at arguing them sometimes or gets topics flatly wrong.
USA had no business being in Vietnam. However, that is VERY EASY to say in HINDSIGHT. With facts on hand, there was more logic behind it. USA didn't lose in Vietnam, the South Vietnamese regime lost because they failed to create legitimacy with the people and they turned to Ho Chi Minh. If you read about Ho Chi Minh, he could have clearly been Pro-Democratic and a USA ally if we had better policy in the late 1940s/early 1950s. We sided with France over him and that pushed him towards the USSR and China due to lack of support. He really wasn't a true Communist but a Vietnamese National (a lot came out after that). So Ras is right, never should have been there.
Middle East - Still learning more about that conflict. 95% of people supported going into Afghanistan at the time so hard to argue against that one but Iraq was extremely controversial and, even at the time, dubious.
Can the USA win these type wars? With its current culture, "no". If the USA had a united culture and a plan, sure they could win. How do you win in Afghanistan? Simple, you push the population to convert to your religion (away from Islam) and your way of living. Effectively, you do what Greece, Mongolia, Rome, Arabia, and other great Empires that dominated the Middle East did and force them to convert to your way of life. People who oppose this change, you kill off.
These countries are not unbeatable. Afghanistan was successfully conquered and help by Persia, Macedon, Arabia Caliphate, Persia again, Turkish Empires, Mongolia, and Mongolia part 2 (Timur lane). All of these societies pushed their culture on the region to control it.
Now whether that is worth it to win is the question and it really isn't work that kind of effort to win. Ras is right, better to just stay out or find other paths to win.