Truman was thought of a the man who lost China to the communists and no one wanted to be the president who lost SE Asia. Nixon could have ended the war we never should have entered. Early on I was a supporter with a brother and many friends over there. As years passed I read more, watch the first two episodes of Ken Burn's Vietnam and you'll learn why this was a mistake. Nixon was just like the rest, he did not want to lose SE Asia.
Ellsberg was told by McNamara to study the entire history of Viet Nam, he did and this former marine patriot became disillusioned and shocked and how EVERY president bullshitted the American people.
He tried to change this, was rebuffed and thus=The Pentagon Papers.
Nixon and Kissinger are responsible for much of the chaos that roils South America today.