decades of US plans to kill Castro: Castro won

"Fleming, it is claimed, told Kennedy, that killing Fidel Castro was not simply enough, he had to be thoroughly humiliated." "Other agents studied the possibility of killing Castro while he was diving. Plans were discussed which considered infecting his air supply with a biological agent. But Desmond Fitzgerald, the CIA's former head of Cuban operations said he bought two books on Caribbean mollusks, to find a seashell suitable to hold an explosive device, which would kill the communist leader on the sea bed. Another plan, which seemed similar to one discussed at the Kennedy dinner table involved a CIA campaign describing Castro as the anti-Christ, while a US submarine would light up the sky with starbursts announcing the Second Coming." (thanks Amir)