Groupthink refers to Irving Janis' analysis of poor decision-making that led to major failures. For example, before the Pearl Harbor attack, military intelligence had information about a possible Japanese attack in the Pacific but complacent commanders decided against air reconnaissance or raising alert levels. As a result, the Pearl Harbor attack caught the base virtually defenseless. Additionally, in 1961 the Bay of Pigs invasion aimed to overthrow Fidel Castro using CIA-trained Cuban exiles but nearly all the invaders were soon killed or captured, humiliating the US and pushing Cuba closer to allying with the Soviet Union.