Final answer:
The Bay of Pigs failure was largely due to Groupthink, as Kennedy and his advisers incorrectly believed that the Cuban people would support an uprising against Castro, leading to a poorly planned and executed operation that ended in disaster.
Step-by-step explanation:
John F. Kennedy's Bay of Pigs failure was caused in large part by Groupthink. During this failed 1961 covert operation, Kennedy and his advisers overestimated the possibility of a popular uprising in Cuba against Fidel Castro's regime, largely ignoring the likelihood that the Cuban people would not support the invasion as they were still supportive of or wary of switching back to a U.S.-backed regime similar to Batista's.
The invasion, intended to trigger a revolt and overthrow Castro, ended disastrously when Cuban troops foiled the poorly planned and executed operation.