These odes to Eisenhower’s foreign-policy judgment always end with his retirement in 1961 to a farm in Gettysburg, Pennsylvania. But Eisenhower lived for another eight years. He didn’t retreat from public life and paint pictures of world leaders like George W. Bush, but remained a major figure on the national stage. He enjoyed enormous respect and credibility as a war hero, the Republican Party’s elder statesman, and after 1964, one of only two ex-presidents still alive (the other being Harry Truman). Lyndon Johnson relied heavily on the counsel of a man who knew the burdens of office.

With the United States on the brink of a major intervention in Vietnam, the nation needed Ike’s sense of caution and restraint, and his recognition that the use of force can trap a country in foreign adventures. Unfortunately, Eisenhower’s good judgment vanished during the 1960s, as he urged officials into ever-greater escalation in Vietnam. As Andrew Johns detailed in his book on the Republican Party and the war, Vietnam’s Second Front, Eisenhower sought victory in Vietnam by almost any means.

In February 1965, Eisenhower spent two hours explaining to LBJ’s inner circle the vital importance of “denying Southeast Asia to the Communists,” and the need to massively expand the bombing of North Vietnam. But air power didn’t work, and by the summer of 1965, South Vietnam was crumbling in the face of a Communist insurgency. LBJ faced a critical decision about whether to send large numbers of American troops, and Ike urged the president to Americanize the war. “When you once appeal to force in an international situation involving military help for a nation, you have to go all out!” Eisenhower told Johnson. “We are not going to be run out of a free country that we helped establish.”

As the fighting descended into stalemate, Eisenhower resisted a negotiated peace: “I have no patience whatsoever with the people that want to pull out of Vietnam at once, or are otherwise prepared to surrender principle.” In 1966, he spoke to LBJ by phone, telling him that winning in Vietnam was more important than fighting poverty or reaching the moon. The following year, Eisenhower urged Congress to declare war on North Vietnam, so that Americans would stay focused on the mission rather than getting distracted by the Great Society. Meanwhile, he exhorted LBJ to expand the war. “This respecting of boundary lines on the map, I think you can overdo it,” he said. The U.S. should pursue the Communists into Laos, Cambodia, and even North Vietnam, and ignore the “‘kooks’ and ‘hippies’ and all the rest that are talking about surrendering.”

The plan was so hawkish it made Richard Nixon nervous. Nixon felt that Ike may be right from a “military standpoint,” but the diplomatic and political consequences would be dangerous, running “a substantial risk of widening the ground conflict in Vietnam.”