Perhaps not in casualties but as far as prestige and standing in the world were concerned, the Bay of Pigs invasion of 1961 was the worst disaster to befall the USA since the War of 1812 when British forces burned the White House. Badly planned, badly organized, the affair was littered with mistakes from start to finish - not least with an inept performance by John F Kennedy and his new administration.
Supposedly an attempt by Cuban exiles to regain their homeland, the whole operation was funded and equipped by the USA. When things began to go wrong with the landings at Playa Larga and Playa Giron on the southern coast of Cuba President Kennedy and his advisers began overruling military decisions with the result that the invading Brigade 2506 - made up of Cuban exiles - was left with little or no air cover, limited ammunition and no easy escape.
Fidel Castro made great play of his success and American failure at the Bay of Pigs. He, like Nikita Khrushchev, thought Kennedy was weak: the Cuban Missile Crisis of the following year was almost an inevitable consequence of the disaster.