Theres so many weird things about it and i dont think ive ever heard a solid explanation for everything.
I reckon (and it’s the same thing I believe about 9/11), it’s a mixture of incompetence/complacency on behalf of US intelligence.
Think about how many concurrent tips/investigations into threats against the president the feds must deal with at any one time. I think, like 9/11, they probably had knowledge of a potential plot and failed to stop it, without being “involved”.
I’m sure theres a good chance the CIA/feds had their hands in it financially somewhere, in the sense that they’re always paying/arming groups all around the world - again, similar to 9/11 imo.
But did a bunch of agents sit down in a smoky room and decide to waste Kennedy? I doubt it. Maybe it was some kind of CIA asset they lost control of - “hey if we create a credible threat against the president maybe he will give us more license to attack Cuba” or whatever.