We did learn from Vietnam, "Thank A Vet", since we showed disrespect for the Vietnam Vet.  War is a business, by product is the wounded and the dead, businesses make money. Intervention is who we are, either we go it alone or others join us, this is our foreign policy, I feel it was the reason for 911.   Our government not telling us the truth, the norm.
My two cents, Vietnam is best left to those who served, the wounds will never heal.  As a veteran I will say this, if you did not serve,  best keep your  views to yourself, reason I did not watch.   Of all the conflicts and that is what Vietnam was, not a war, never declared, it was a conflict like Korea, Vietnam brings out strong reactions from both sides.  Hawkeye from M*A*S*H stated it best about war: "We find new and better ways to destroy the human body", I believe in this strongly along with war being a business.  Learn from Vietnam the disrespect you shown to those who served,  the disrespect of the flag, far worse than today.