The thought that the attacks of September 11, 2001, could have been prevented is frustrating. Intelligence indicators went unheeded, including information from 1998 suggesting terrorist plans to fly an explosive-laden aircraft into the World Trade Center or detonate explosives at an airport. We learn that the director of Central Intelligence, George Tenet, stated in December 1998 that the United States was "at war" with Osama bin Laden; he urged intelligence officials to spare no resources in the effort against Al Qaeda. In the summer of 2001 intelligence received information that bin Laden associates "were planning attacks in the United States with explosives," and thirty-three communications that indicated a "possible, imminent terrorist attack." Viewing evidence in hindsight, however, and considering it outside the context of all available information, can lead to simplistic conclusions. Broadening the inquiry to include other cases of strategic surprise can help us learn the right lessons from 9-11.
Nearly sixty years before terrorists struck Washington and New York, half the Japanese fleet moved to within striking distance of Oahu and achieved complete surprise at Pearl Harbor. Revisiting why intelligence indicators did not generate warnings and defensive action before December 7, 1941, seems relevant to September 11, 2001.
After Pearl Harbor, Congress also held hearings that evoked similar emotions of disappointment. A March 1941 report stated that a Japanese declaration of war might be preceded "by a surprise attack on Oahu including ships and installations on Pearl Harbor" and suggested patrols to prevent "surface or air surprise." A week before the attack, an analyst suggested that Japanese radio pattern changes indicated "active operations on a large scale." On December 3, Washington learned that Japanese diplomatic and consular posts were to destroy their codes and secret documents. On December 6, the FBI in Honolulu witnessed members of the Japanese consulate burning papers. Hours before the attack, a U.S. Navy destroyer identified a Japanese submarine in the harbor. Then as today it seemed that officials should have taken defensive action.
In her classic study Pearl Harbor: Warning and Decision (1962), Roberta Wohlstetter concluded that the surprise at Pearl Harbor was not surprising at all. Evidence of an impending attack was muted by the "noise" of conflicting information. Moreover, false alarms had desensitized officials to warnings. Bureaucratic barriers and preserving the secrecy of intelligence sources prevented analysts from connecting disparate indicators.
Although we may never eliminate the possibility of strategic surprise, we can reduce that possibility. The 9-11 attacks appear unprecedented in their brutality against innocent Americans, but we must resist viewing them in isolation. Many of the same causes of the Pearl Harbor surprise were present before September 11. Wohlstetter's book is representative of a rich literature on the subject of strategic surprise, studies generated in large measure by fears of a Soviet thermonuclear attack. History, however, cannot provide us with a specific plan of action to foil future attacks. But it can help us ask the right questions and avoid oversimplification.
Defending our homeland and our interests abroad requires enduring commitment, resolute action, and constant reassessment. As Sir Michael Howard reminds us, history may not be able to make us clever for the next time, but it can make us wise forever.