n recent weeks, President Bush and his administration have mounted a spirited defense of his Iraq policy, the Patriot Act and, especially, a program to wiretap civilians, often reaching back into American history for precedents to justify these actions. It is clear that the president believes that he is acting to protect the security of the American people. It is equally clear that both his belief and the executive authority he claims to justify its use derive from the terrorist attacks of Sept. 11, 2001.

A myriad of contested questions are obviously at issue here ­ foreign policy questions about the danger posed by Iraq, constitutional questions about the proper limits on executive authority, even political questions about the president's motives in attacking Iraq. But all of those debates are playing out under the shadow of Sept. 11 and the tremendous changes that it prompted in both foreign and domestic policy.

Whether or not we can regard Sept. 11 as history, I would like to raise two historical questions about the terrorist attacks of that horrific day. My goal is not to offer definitive answers but rather to invite a serious debate about whether Sept. 11 deserves the historical significance it has achieved.

My first question: where does Sept. 11 rank in the grand sweep of American history as a threat to national security? By my calculations it does not make the top tier of the list, which requires the threat to pose a serious challenge to the survival of the American republic.

Here is my version of the top tier: the War for Independence, where defeat meant no United States of America; the War of 1812, when the national capital was burned to the ground; the Civil War, which threatened the survival of the Union; World War II, which represented a totalitarian threat to democracy and capitalism; the cold war, most specifically the Cuban missile crisis of 1962, which made nuclear annihilation a distinct possibility.

Sept. 11 does not rise to that level of threat because, while it places lives and lifestyles at risk, it does not threaten the survival of the American republic, even though the terrorists would like us to believe so.

My second question is this: What does history tell us about our earlier responses to traumatic events?

My list of precedents for the Patriot Act and government wiretapping of American citizens would include the Alien and Sedition Acts in 1798, which allowed the federal government to close newspapers and deport foreigners during the "quasi-war" with France; the denial of habeas corpus during the Civil War, which permitted the pre-emptive arrest of suspected Southern sympathizers; the Red Scare of 1919, which emboldened the attorney general to round up leftist critics in the wake of the Russian Revolution; the internment of Japanese-Americans during World War II, which was justified on the grounds that their ancestry made them potential threats to national security; the McCarthy scare of the early 1950's, which used cold war anxieties to pursue a witch hunt against putative Communists in government, universities and the film industry.

In retrospect, none of these domestic responses to perceived national security threats looks justifiable. Every history textbook I know describes them as lamentable, excessive, even embarrassing. Some very distinguished American presidents, including John Adams, Abraham Lincoln and Franklin Roosevelt, succumbed to quite genuine and widespread popular fears. No historian or biographer has argued that these were their finest hours.

What Patrick Henry once called "the lamp of experience" needs to be brought into the shadowy space in which we have all been living since Sept. 11. My tentative conclusion is that the light it sheds exposes the ghosts and goblins of our traumatized imaginations. It is completely understandable that those who lost loved ones on that date will carry emotional scars for the remainder of their lives. But it defies reason and experience to make Sept. 11 the defining influence on our foreign and domestic policy. History suggests that we have faced greater challenges and triumphed, and that overreaction is a greater danger than complacency.