William F. Buckley 
See You Later, Alligator [EPUB ebook] 

In the New York Times–bestselling spy series, Agent Oakes is in Cuba for secret negotiations with Che Guevara—on a mission that soon turns deadly. From his 1st day in office, President Kennedy has been bedeviled by Cuba. The CIA forced the Bay of Pigs invasion down his throat, resulting in lost lives, international embarrassment, and a new low in America’s relationship with the Caribbean. More than anything, Kennedy wants Cuba contained. Brute force didn’t work; it’s time to try a subtler approach—and there is no spy more tactful than Blackford Oakes.   The CIA calls it Operation Alligator: a top secret back-channel negotiation to put Cuba and the United States on better footing. Oakes goes south to meet with Castro’s right-hand man, the notorious Che Guevara, in hopes of finding common ground between their countries. Instead, he discovers a sinister Communist plot that could destabilize the hemisphere, and lead the US president to his doom.  See You Later, Alligator is the 6th book in the Blackford Oakes Mysteries, but you may enjoy reading the series in any order.