Cuban Project by late August, the Soviet military build-up in Cuba disgruntled the Kennedy administration. The fear of open military retaliation against the United States and Berlin for the US covert operations in Cuba slowed down the operation. By October, as the Cuban Missile Crisis heated up, President Kennedy demanded the cessation of Operation Mongoose. Operation Mongoose formally ceased its activities at the end of 1962. The first assassination plots began in the late summer of 1960, according to the Church Committee’s documentation. Some of the plots and ideas ranged from “poisoned pills, an exploding seashell, and a planned gift of a
Cuban Missile Crisis to endorse the missile swap but others continued to oppose the offer. Finally, Kennedy ended the debate. "We can't very well invade Cuba with all its toil and blood," Kennedy said, "when we could have gotten them out by making a deal on the same missiles on Turkey. If that's part of the record, then you don't have a very good war." Kennedy immediately responded, issuing a statement calling the letter "an important and constructive contribution to peace." He continued this with a formal letter: Kennedy's planned statement would also contain suggestions he had received from his adviser Schlesinger Jr.