The decision shocked many at the time as Kissinger, then US national security adviser and secretary of state under President Richard Nixon, played a major role in US military strategy in the final stages of the 1955-75 Vietnam conflict. “I am even more surprised than I was at the time that the committee could come to such a bad decision,” said Stein Tønnesson, a professor at the Peace Research Institute Oslo who reviewed the documents.
Kissinger and Tho reached the January 1973 Paris peace accords, under which Washington completed a military withdrawal from South Vietnam, having largely ended offensives and avoided combat against the communist North in the face of worsening troop morale and huge anti-war protests in America.