.On September 11, 2001, four passenger planes were hijacked by terrorists. Two of the planes were flown into the twin towers of the World Trade Center (WTC) in New York City, causing huge fires that led to the collapse of the towers less than two hours later. One plane crashed into the Pentagon building in Washington, D.C. The last plane crashed in a field in Pennsylvania; it is believed the hijackers had planned to also crash this plane into a building or landmark, but were foiled by the actions of the plane’s passengers. Many of these horrific events, including the second plane’s crash into the World Trade Center and the collapse of the towers, were witnessed live by millions of television viewers. It was by far the worst terrorist attack on American soil; conservative columnist George F. Will labeled it “the most lethal terrorism in human experience.”

As the dust settled in New York and Washington, Americans were left to ponder what the attacks meant for the nation. In search of a historical precedent or point of comparison, many Americans reached back to Japan’s surprise assault on Pearl Harbor on December 7, 1941, another “day of infamy” in which the United States was suddenly attacked. In both instances, a seemingly secure nation was jolted by massive assaults on its own soil. “As Pearl Harbor snapped America out of a false sense of security,” NBC news anchor and author Tom Brokaw writes, “September 11 had a similar effect on young Americans.”

The comparisons Brokaw and others made between the two dates dealt not only with the attacks themselves, but also how the American people responded to them. Many people wondered whether the resolve and unity shown by the American people in 1941 would be matched in 2001. Others wondered whether September 11 would become a defining experience for this current generation of Americans, much as Pearl Harbor had been for members of a previous generation. In attempting to answer these questions, it is instructive to note both the parallels and differences between the two events.

Casualties and perpetrators
Both Pearl Harbor and the September 11 attacks resulted in a large loss of human life. The attack on Pearl Harbor killed 2,388 people. The September 11 carnage was even larger, although an exact number was difficult to ascertain at first. In the initial weeks following September 11, the rough media consensus for the total number of fatalities at the WTC, the Pentagon, and in Pennsylvania was six or seven thousand (numbers cited by some of the articles in this volume). As weeks and months went by, that number consistently shrank, eventually reaching three thousand.

The September 11 casualties were not only numerically larger than a military attack against American military targets. Most of the casualties were sailors or soldiers; of the 2,388 people killed, forty-eight were civilians. For the most part, the September 11 attacks were directed not at soldiers or military targets, but at civilians going about their everyday jobs. For many, the fact that the September 11 terrorists targeted civilians made these acts even more outrageous and horrific than the events of 1941.

Another important difference between the two events was the identities of the attackers. On December 7, 1941, Americans knew who the enemy was—the Japanese Empire—and what its intentions were—to wage war against the United States. On September 11, 2001, Americans knew they had been attacked and perhaps were even at war, but they did not know who the enemy was or what their future intentions were.

In the days following September 11, 2001, some answers to these questions were found. Investigators from the Federal Bureau of Investigation (FBI) and other law enforcement agencies identified the nineteen air passengers that they believed were responsible for the attacks. The presumed terrorists were all men from Middle Eastern countries, including Egypt and Saudi Arabia. Suspicion quickly zeroed in on