Yes, Kennedy did. By botching the invasion of Cuba, he triggered Castro to demand soviet missiles in Cuba to dissuade the US from ever attempting another invasion.
Had Idiot Kennedy provided the Naval and Aerial support the government had promised the Cubans, they would have won, Castro would have been out, and there never would have been Russian missiles in Cuba.
One thing is clear: the official conclusion of the government that a lone gunman killed the president is still not believed by vast numbers of citizens.
I have always believed Oswald was a nut who decided to kill Kennedy, but with what I have seen of the recent deep state activity against Trump, I am now no longer so sure they weren't behind the Kennedy assassination.
On the Nixon tapes, right before one of the erased portions (7 minutes?) Nixon says something about “It might bring up the whole Cuban thing.” (Some of the Watergate guys were Cubans involved in the Bay of Pigs fiasco.)
I always wondered if Nixon thought/knew that it had something to do with the assassination. Later in Haldeman’s book he said he thought that was what the comment was about after hearing it on tape.
Below is one article with some of Haldeman’s comments. The first part of the article is typical anti-Nixon crap. Another thought the article brings up is that it may not have been the Kennedy assassination Nixon was concerned about, but JFK plans for a Castro assassination getting out.
https://www.thehistoryreader.com/military-history/nixons-bay-pigs-secrets/