This collection highlights the causes and consequences of US Intelligence Community’s (IC) failure to foresee the October 1973 Arab-Israeli War, also known as the October War or the Yom Kippur War. A coalition of Arab nations led by Egypt and Syria launched a surprise attack on Israel on October 6, the day of Yom Kippur. Prior to October 6, the CIA concluded that the Arabs would not attack, so the offensive surprised US policymakers as well as Israel. Directorate of Intelligence (DI) analysts believed that Arab military inferiority would militate against an attack on Israel. DI analysis did not explore the possibility that leaders might go to war--even at the risk of losing--to pursue political objectives. According to an internal postmortem, Agency analysis was impaired by preconceptions about Arab military capabilities, information overload, rational actor modeling and groupthink.