I guess I wasn't clear with my statement
I meant to suggest that Cuba was the cause of the JFK assassination from the point of view that all the clandestine projects they were working on for an assassination for Fidel Castro didn't work or were being prevented or discouraged by the US government. This set off a chain of events where they turned the projects they were directing to Cuba instead towards the US president. Basically the same operations and operators that were meant to be directed to Cuba were instead brought to the US and the president.
In a round about way ... Cuba was the cause or catalyst (or one of many causes or catalysts) for the JFK assassination.