During my first trip to Hawaii, I made my way to a place considered sacred by most US citizens, the USS Arizona memorial at Pearl Harbor. Survivors often greet visitors to the memorial, answering questions and retelling their memories of the day that the Japanese attacked the US Pacific Fleet. When it came my turn, I asked what the weather was like that fateful morning. The answer was “like today.” A few puffy clouds dotted the blue

Hawaiian skies, a light breeze pushed ripples across the turquoise water of the harbor, stirring the warm tropical air to create one of the most idyllic anchorages on earth. September 11 also dawned clear and blue over New York City, the kind of late summer day that highlights perfectly the United States’ front door, the spectacular edifice of promise and prosperity that is lower Manhattan. Given the setting, it is no wonder that the events of both Pearl Harbor and September 11 came as a complete shock to eyewitnesses. Neither could have happened on a more pleasant morning.

We now know, however, that initial eyewitness interpretations of both of these surprise attacks, as bolts out of the blue, were incorrect. Indications of what was about to happen were available before the Japanese attack on Pearl Harbor. In fact, one of the accepted tenets of the literature on surprise attacks is that in all cases of so-called intelligence failure, accurate information concerning what is about to transpire can be found in the intelligence system after the fact. It is thus to be expected that revelations will continue about the signals that were in the intelligence pipeline prior to the terrorist attacks of September 11. And as in the aftermath of Pearl Harbor, the US government will hold a series of investigations to discover how organizational shortcomings or mistakes made by specific officials were responsible for the intelligence failure that paved the way for the destruction of the World Trade Center and the attack on the Pentagon.

It is not surprising that similarities exist between the attack on Pearl Harbor and the terrorist attacks of September 11 because both events are examples of a more general international phenomenon—the surprise attack. Despite the fact that they occurred over 50 years apart and involve different kinds of international actors with highly different motivations, a pattern exists in the events leading up to surprise and its consequences. Exploring these similarities can help cast the tragedy of September 11 in a broader context, an important initial step in reducing the likelihood of mass-casualty terrorism in the future.

Warning Signs

Although Pearl Harbor and the September 11 attacks are sometimes depicted as totally unanticipated events, both incidents were preceded by clear indications that the United States faced an imminent threat. Prior to Pearl Harbor, US-Japanese relations had reached a nadir. By the summer of 1941, the administration of US President Franklin Roosevelt had placed economic sanctions on the Japanese to force them to end their war against China. These sanctions were the proximate cause of the Japanese attack. Japanese officials believed that the US embargo against them would ruin their economy, while destruction of the US fleet would provide them with some maneuvering room. They intended to quickly seize resource-rich lands in the Far East, fortify their newly conquered lands, and then reach some sort of negotiated settlement with the United States.

The Roosevelt administration recognized that it faced a crisis with Japan, although senior officials in Washington did not realize that Oahu was in danger until it was too late. In their minds, it made no sense for the Japanese to attack the United States because they simply lacked the economic resources or military capability to defeat the US military in a long war. In an ironic twist, the Roosevelt administration was ultimately proven correct in this estimate. The Japanese attack on Pearl Harbor eliminated the possibility of US acquiescence to the creation of a Japanese empire in the Pacific as well as the eventual peace arrangement Japan hoped to achieve.

The situation that faced the United States was even more clear cut, if not quite as grave, prior to September 11. Various studies and commissions (such as the government’s Gilmore commission) described the ongoing struggle against terrorism and predicted that a significant terrorist attack on the continental United States was a virtual certainty. The United States was actually engaged in a war with Al Qaeda, an international network of terrorist groups, throughout the 1990s. Al Qaeda may have been loosely linked to the militias that battled US Ranger units in Somalia in 1993. Al Qaeda also was involved in the bombing of the office of the program manager for the Saudi Arabian National Guard in Riyadh in November 1995 and in the attack on the Khobar Towers complex in Dahran in July 1996.

These attacks on US interests in 1995 and 1996 changed the way forward deployed US forces operated within the Arabian Peninsula. New “force protection” regulations were promulgated to protect US military personnel, requiring commanders to observe stringent requirements to ensure their safety. In Saudi Arabia, US operational units were consolidated at Prince Sultan Air Base and advisory components were moved to Eskan Village, a housing complex south of Riyadh. Intelligence collection efforts also concentrated on the new threat, providing forces throughout the region with improved tactical and operational warning. At times, US forces were placed at “Threatcon Delta” in expectation of an immediate attack. The hardening of the “target” on the Arabian Peninsula forced Al Qaeda to look for vulnerabilities elsewhere.

Any lingering doubts about the ongoing threat were dispelled by Al Qaeda’s bombing of the US embassies in Kenya and Tanzania in August 1998 and the attack against the USS Cole in October 2000. The United States even returned fire following the 1998 embassy attacks by launching cruise missile strikes against suspected terrorist training camps in Afghanistan and a pharmaceutical plant in Sudan that was believed to have links to Al Qaeda. US government agencies had a clear idea that Osama bin Laden was committed to attacking US interests globally. Bin Laden’s 1998 fatwa represented a declaration of war on the United States and called upon supporters to kill US officials, soldiers, and civilians everywhere around the world. This assessment of bin Laden’s intentions was reflected in a variety of publicly available sources. The US Congressional Research Service published a compelling warning about bin Laden’s campaign of terror entitled “Terrorism: Near Eastern Groups and State Sponsors” on September 10, 2001. A compelling description of bin Laden’s alliance with the Taliban and his political agenda was even published in Foreign Affairs in 1999.