Sad part is none of those proxy/unnecessary wars changed anything. Vietnam is still not a western style democracy. Iraq & Afghan war created a bigger mess by de-stabilizing dictator controlled middle-east countries. ISIS would be impossible to become powerful under Saddam. Afghanistan is still a backward radical Islamist country. What a bloody waste of blood & treasure. Even worst part is United States is in bigger debt from these wars. And the debt keeps getting bigger from Ukraine war.
Proxy wars killed a lot of people, ruined a lot of lives, left a lot of kids without a parent or parents, while making a lot of people who invest in war, a whole lot richer. And as you said, nothing changed afterward. Rinse and repeat.
My only brother was a U.S. Army Vietnam Vet. He was stationed in Cu Chi 1966-67, and died at the way too young age of 51 in 1995 of a massive heart attack. Left his widow and four kids. My two uncles from both sides of the family served overseas with the Army in WWII, came home, but died even younger than 51. One of those uncles was an only son. My great-uncle on my mother's side was the only son in that family, and served with the Canadian Expeditionary Forces in France in WWI. He was killed two months before the Armistice, and is buried in Wimille, France in a British Military Cemetery. He was 25. So many young people never even had the chance to live their lives, and the fat cat investors, just got fatter.