Some people think it was a dud.
While others think it was a fake.
Useful summary from Q&O.
Ben Johnson blames Bill Clinton and Jimmy Carter.
I think you can go right back to Harry Truman on this one. He should have allowed MacArthur to win the war. Truman provided the still commonly-implemented model of wasting American money and lives in pursuit of lesser objectives than victory. In the case of Vietnam, avoiding aiming at victory ultimately produced defeat. The original version of the policy was so good a choice, that, technically speaking, we’re still engaged in Harry Truman’s unfinished war.