Worse yet, history teaches that such plays for credibility do not turn out well.

Immediately following the final session on June 4 Kennedy sat for a previously scheduled interview with New York Times columnist James Reston at the American embassy. Kennedy was reeling from his meetings with Khrushchev, famously describing the meetings as the “roughest thing in my life.” Reston reported that Kennedy said just enough for Reston to conclude that Khrushchev “had studied the events of the Bay of Pigs” and that he had “decided that he was dealing with an inexperienced young leader who could be intimidated and blackmailed.” Kennedy said to Reston that Khrushchev had “just beat [the] hell out of me” and that he had presented Kennedy with a terrible problem: “If he thinks I’m inexperienced and have no guts, until we remove those ideas we won’t get anywhere with him. So we have to act.”…

The following year brought the Cuban missile crisis, another sequel to Khrushchev’s reading of Kennedy’s weakness. Close as the Cuban missile crisis brought the two sides to war, however, it was perhaps not the most consequential effect of Khrushchev’s reading of Kennedy’s weakness. Persuaded that he needed further to demonstrate “fearlessness and backbone,” in the words of William Manchester, Kennedy observed to Reston that the only place where the Communists were challenging the West in a shooting war was in Southeast Asia. Summarizing Kennedy’s own evaluation of the aftermath of the Vienna conference in his 2003 biography of Kennedy, Robert Dallek writes that Kennedy “now needed to convince Khrushchev that he could not be pushed around, and the best place currently to make U.S. power credible seemed to be in Vietnam.”

http://www.weeklystandard.com/the-kennedy-khrushchev-conference-for-dummies/article/16242