The U.S. exited World War II believing that strength would win every war. How did the events in the 1960s during JFK's administration support this idea and did they not support this idea? Be specific.
I would argue that the events of President Kennedy’s time in office can neither prove nor disprove this idea. The most that we can say is that these events tell us that strength will only win those wars where it is truly exerted. If the US is not willing to throw its full strength into a war (as it did in WWII) it will not necessarily win. There are two main events in Kennedy’s presidency that illustrate this. (Neither of these events were actually full-scale wars so they are not the best pieces of evidence for the validity of this statement.)
The one event in Kennedy’s foreign affairs that was clearly successful was the Cuban Missile Crisis. In that crisis, the US imposed a military blockade on Cuba to prevent the USSR from bringing more missiles (that could be used with nuclear warheads) to the island. The Soviets backed down and removed the missiles that were already there. We can argue that this proves that strength will win wars because the US gave a credible threat to go to war over the missiles. Since the US was willing to impose the blockade and to credibly threaten to invade Cuba, it was able to win this conflict.
A second event in Cuba showed that the US would not win in situations where it was not willing to deploy its full strength. This was the Bay of Pigs invasion that happened more than a year before the missile crisis. In the Bay of Pigs invasion, Kennedy gave CIA-trained Cuban rebels help in invading Cuba. However, he was not willing to provide them with overt American support. This meant that he did not give the landings any American air support and the landings failed. This clearly showed that strength will only win wars (or at least battles) if the US is willing to use it.
Of course, President Kennedy presided over some of the escalation of American involvement in Vietnam. However, American involvement at the time of his death was relatively small and the outcome of the war was not clear at that point. Therefore, I am not using Vietnam as part of my evidence in this answer.
President Kennedy did not lead the US in any wars. Therefore, it is hard to say for sure whether events in his presidency prove that strength will win every war. They do imply, however, that strength will certainly not win wars if the US is not willing to deploy that strength against the enemy.