At the turn of the millennium, the world was braced for terrible things. Most “rational” worries were tied to an anticipated computer glitch, the Y2K problem, and even the most scientifically oriented of people seemed temporarily at the mercy of powerful mythic forces. Imagined hobgoblins leapt from hard drives directly into nightmares. Airlines canceled flights scheduled for the first day of the new year, citing fears that the computers for the traffic-control system would not work. The calendar as such had not previously been a source of dread, but all at once, time itself held a new danger. As the year 2000 approached, I bought bottled water and extra cans of tuna fish. I even withdrew a large amount of cash from the bank. Friends mocked me, then admitted to having done similar things. There were no dances-of-death or outbreaks of flagellant cults, but a millennial fever worthy of medieval superstition infected the most secular of cultures. Of course, the mystical date came and went, the computers did fine, airplanes flew and the world went back to normal.

Then came September 11, 2001, the millennial catastrophe–just a little late. Airplanes fell from the sky, thousands died and an entirely new kind of horror gripped the human imagination. Time, too, played its role, but time as warped by television, which created a global simultaneity, turning the whole human race into a witness, as the awful events were endlessly replayed, as if those bodies leaping from the Twin Towers would never hit the ground. Nightmare in broad daylight. New York’s World Trade Center collapsed not just onto the surrounding streets but into the hearts of every person with access to CNN. Hundreds of millions of people instinctively reached out to those they loved, grateful to be alive. Death had shown itself in a new way. But if a vast throng experienced the terrible events of 9/11 as one, only one man, the President of the United States, bore a unique responsibility for finding a way to respond to them.

George W. Bush plumbed the deepest place in himself, looking for a simple expression of what the assaults of September 11 required. It was his role to lead the nation, and the very world. The President, at a moment of crisis, defines the communal response. A few days after the assault, George W. Bush did this. Speaking spontaneously, without the aid of advisers or speechwriters, he put a word on the new American purpose that both shaped it and gave it meaning. “This crusade,” he said, “this war on terrorism.”

Crusade. I remember a momentary feeling of vertigo at the President’s use of that word, the outrageous ineptitude of it. The vertigo lifted, and what I felt then was fear, sensing not ineptitude but exactitude. My thoughts went to the elusive Osama bin Laden, how pleased he must have been, Bush already reading from his script. I am a Roman Catholic with a feeling for history, and strong regrets, therefore, over what went wrong in my own tradition once the Crusades were launched. Contrary to schoolboy romances, Hollywood fantasies and the nostalgia of royalty, the Crusades were a set of world-historic crimes. I hear the word with a third ear, alert to its dangers, and I see through its legends to its warnings. For example, in Iraq “insurgents” have lately shocked the world by decapitating hostages, turning the most taboo of acts into a military tactic. But a thousand years ago, Latin crusaders used the severed heads of Muslim fighters as missiles, catapulting them over the fortified walls of cities under siege. Taboos fall in total war, whether crusade or jihad.

For George W. Bush, crusade was an offhand reference. But all the more powerfully for that, it was an accidental probing of unintended but nevertheless real meaning. That the President used the word inadvertently suggests how it expressed his exact truth, an unmasking of his most deeply felt purpose. Crusade, he said. Later, his embarrassed aides suggested that he had meant to use the word only as a synonym for struggle, but Bush’s own syntax belied that. He defined crusade as war. Even offhandedly, he had said exactly what he meant.

Osama bin Laden was already understood to be trying to spark a “clash of civilizations” that would set the West against the whole House of Islam. After 9/11, agitated voices on all sides insisted that no such clash was inevitable. But crusade was a match for jihad, and such words threatened nothing less than apocalyptic conflict between irreconcilable cultures. Indeed, the President’s reference flashed through the Arab news media. Its resonance went deeper, even, than the embarrassed aides expected–and not only among Muslims. After all, the word refers to a long series of military campaigns, which, taken together, were the defining event in the shaping of what we call Western civilization. A coherent set of political, economic, social and even mythological traditions of the Eurasian continent, from the British Isles to the far side of Arabia, grew out of the transformations wrought by the Crusades. And it is far from incidental still, both that those campaigns were conducted by Christians against Muslims, and that they, too, were attached to the irrationalities of millennial fever.

If the American President was the person carrying the main burden of shaping a response to the catastrophe of September 11, his predecessor in such a grave role, nearly a thousand years earlier, was the Catholic pope. Seeking to overcome the century-long dislocations of a postmillennial Christendom, he rallied both its leaders and commoners with a rousing call to holy war. Muslims were the infidel people who had taken the Holy Land hundreds of years before. Now, that occupation was defined as an intolerable blasphemy. The Holy Land must be redeemed. Within months of the pope’s call, 100,000 people had “taken the cross” to reclaim the Holy Land for Christ. As a proportion of the population of Europe, a comparable movement today would involve more than a million people, dropping everything to go to war.

In the name of Jesus, and certain of God’s blessing, crusaders launched what might be called “shock and awe” attacks everywhere they went. In Jerusalem they savagely slaughtered Muslims and Jews alike–practically the whole city. Eventually, Latin crusaders would turn on Eastern Christians, and then on Christian heretics, as blood lust outran the initial “holy” impulse. That trail of violence scars the earth and human memory even to this day–especially in the places where the crusaders wreaked their havoc. And the mental map of the Crusades, with Jerusalem at the center of the earth, still defines world politics. But the main point, in relation to Bush’s instinctive response to 9/11, is that those religious invasions and wars of long ago established a cohesive Western identity precisely in opposition to Islam, an opposition that survives to this day.

With the Crusades, the violent theology of the killer God came into its own. To save the world, in this understanding, God willed the violent death of God’s only beloved son. Here is the relevance of that mental map, for the crusaders were going to war to rescue the site of the salvific death of Jesus, and they displayed their devotion to the cross on which Jesus died by wearing it on their breasts. When Bush’s remark was translated into Arabic for broadcast throughout the Middle East, the word “crusade” was rendered as “war of the cross.”

Before the Crusades, Christian theology had given central emphasis to the resurrection of Jesus, and to the idea of incarnation itself, but with the war of the cross, the bloody crucifixion began to dominate the Latin Christian imagination. A theology narrowly focused on the brutal death of Jesus reinforced the primitive notion that violence can be a sacred act. The cult of martyrdom, even to the point of suicidal valor, was institutionalized in the Crusades, and it is not incidental to the events of 9/11 that a culture of sacred self-destruction took equally firm hold among Muslims. The suicide-murderers of the World Trade Center, like the suicide-bombers from the West Bank and Gaza, exploit a perverse link between the willingness to die for a cause and the willingness to kill for it. Crusaders, thinking of heaven, honored that link too.

Here is the deeper significance of Bush’s inadvertent reference to the Crusades: Instead of being a last recourse or a necessary evil, violence was established then as the perfectly appropriate, even chivalrous, first response to what is wrong in the world. George W. Bush is a Christian for whom this particular theology lives. While he identified Jesus as his favorite “political philosopher” when running for President in 2000, the Jesus of this evangelical President is not the “turn the other cheek” one. Bush’s savior is the Jesus whose cross is wielded as a sword. George W. Bush, having cheerfully accepted responsibility for the executions of 152 death-row inmates in Texas, had already shown himself to be entirely at home with divinely sanctioned violence. After 9/11, no wonder it defined his deepest urge.

But sacred violence, once unleashed in 1096, as in 2001, had a momentum of its own. The urgent purpose of war against the “enemy outside”–what some today call the “clash of civilizations”–led quickly to the discovery of an “enemy inside.” The crusaders, en route from northwestern Europe to attack the infidel far away, first fell upon, as they said, “the infidel near at hand”–Jews. For the first time in Europe, large numbers of Jews were murdered for being Jews. A crucifixion-obsessed theology saw God as willing the death of Jesus, but in the bifurcated evangelical imagination, Jews could be blamed for it, and the offense the crusaders took was mortal.

The same dynamic–war against an enemy outside leading to war against an enemy inside–can be seen at work today. It is a more complex dynamic now, with immigrant Muslims and people of Arabic descent coming under heavy pressure in the West. In Europe, Muslims are routinely demonized. In America, they are “profiled,” even to the point of being deprived of basic rights. But at the same time, once again, Jews are targeted. The broad resurgence of anti-Semitism, and the tendency to scapegoat Israel as the primary source of the new discord, reflect an old tidal pull. This is true notwithstanding the harsh fact that Ariel Sharon’s government took up the Bush “dead or alive” credo with enthusiasm and used the “war on terrorism” to fuel self-defeating overreactions to Palestinian provocations. But some of Israel’s critics fall into the old pattern of measuring Jews against standards to which no one else is held, not even our President. That the war on terrorism is the context within which violence in Israel and Jerusalem has intensified should be no surprise. It wasn’t “Israel” then, but conflict over Jerusalem played exactly such a flashpoint role a thousand years ago.

The Crusades proved to have other destructive dynamics as well. The medieval war against Islam, having also targeted Europe’s Jews, soon enough became a war against all forms of cultural and religious dissent, a war against heresy. As it hadn’t been in hundreds of years, doctrine now became rigidly defined in the Latin West, and those who did not affirm dominant interpretations–Cathars, Albigensians, Eastern Orthodox–were attacked. Doctrinal uniformity, too, could be enforced with sacred violence. When the US Attorney General defines criticism of the Administration in wartime as treason, or when Congress enacts legislation that justifies the erosion of civil liberties with appeals to patriotism, they are enacting a Crusades script.

All of this is implicit in the word that President Bush first used, which came to him as naturally as a baseball reference, to define the war on terrorism. That such a dark, seething religious history of sacred violence remains largely unspoken in our world does not defuse it as an explosive force in the human unconscious. In the world of Islam, of course, its meaning could not be more explicit, or closer to consciousness. The full historical and cultural significance of “crusade” is instantly obvious, which is why a howl of protest from the Middle East drove Bush into instant verbal retreat. Yet the very inadvertence of his use of the word is the revelation: Americans do not know what fire they are playing with. Osama bin Laden, however, knows all too well, and in his periodic pronouncements, he uses the word “crusade” to this day, as a flamethrower.

Religious war is the danger here, and it is a graver one than Americans think. Despite our much-vaunted separation of church and state, America has always had a quasi-religious understanding of itself, reflected in the messianism of Puritan founder John Winthrop, the Deist optimism of Thomas Jefferson, the embrace of redemptive suffering that marked Abraham Lincoln and, for that matter, the conviction of Eisenhower’s Secretary of State, John Foster Dulles, that Communism had to be opposed on a global scale if only because of its atheism. But never before has America been brought deeper into a dynamite-wired holy of holies than in our President’s war on terrorism. Despite the post-Iraq toning down of Washington’s rhetoric of empire, and the rejection of further crusader references–although Secretary of State Colin Powell used the word this past March–Bush’s war openly remains a cosmic battle between nothing less than the transcendent forces of good and evil. Such a battle is necessarily unlimited and open-ended, and so justifies radical actions–the abandonment, for example, of established notions of civic justice at home and of traditional alliances abroad.

A cosmic moral-religious battle justifies, equally, risks of world-historic proportioned disaster, since the ultimate outcome of such a conflict is to be measured not by actual consequences on this earth but by the earth-transcending will of God. Our war on terrorism, before it is anything else, is thus an imagined conflict, taking place primarily in a mythic realm beyond history.

In waging such a “war,” the enemy is to be engaged everywhere and nowhere, not just because the actual nihilists who threaten the social order are faceless and deracinated but because each fanatical suicide-bomber is only an instance of the transcendent enemy–and so the other face of us. Each terrorist is, in effect, a sacrament of the larger reality, which is “terrorism.” Instead of perceiving unconnected centers of inhuman violence–tribal warlords, Mafia chieftains, nationalist fighters, xenophobic Luddites–President Bush projects the grandest and most interlocking strategies of conspiracy, belief and organization. By the canonization of the war on terrorism, petty nihilists are elevated to the status of world-historic warriors, exactly the fate they might have wished for. This is why the conflict readily bleeds from one locus to another–Afghanistan then, Iraq now, Iran or some other land of evil soon–and why, for that matter, the targeted enemies are entirely interchangeable–here Osama bin Laden, there Saddam Hussein, here the leader of Iran, there of North Korea. They are all essentially one enemy–one “axis”–despite their differences from one another, or even hatred of one another.

Hard-boiled men and women who may not share Bush’s fervent spirituality can nonetheless support his purpose because, undergirding the new ideology, there is an authentic global crisis that requires an urgent response. New technologies are now making it possible for small groups of nihilists, or even single individuals, to wreak havoc on a scale unprecedented in history. This is the ultimate “asymmetric threat.” The attacks of 9/11, amplified by the murderous echo of the anthrax mailer, the as-yet-unapprehended psychopath who sent deadly letters to journalists and government officials in the weeks after 9/11, put that new condition on display for all the world to see. Innovations in physics, biology, chemistry and information technology–and soon, possibly, in nanotechnology and genetic engineering–have had the unforeseen effect of threatening to put in a few hands the destructive power that, in former times, could be exercised only by sizable armies. This is the real condition to which the Bush Administration is responding. The problem is actual, if not yet fully present.

So, to put the best face on the Bush agenda (leaving aside questions of oil, global market control and economic or military hegemony), a humane project of antiproliferation can be seen at its core. Yet a nation that was trying to promote the proliferation of weapons of mass destruction, especially nuclear weapons, would behave precisely as the Bush Administration has behaved over the past three years. The Pentagon’s chest-thumping concept of “full spectrum dominance” itself motivates other nations to seek sources of countervailing power, and when the United States actually goes to war to impose its widely disputed notion of order on some states, but not others, nations–friendly as well as unfriendly–find themselves with an urgent reason to acquire some means of deterring such intervention.

The odd and tragic thing is that the world before Bush was actually nearing consensus on how to manage the problem of the proliferation of weapons of mass destruction, and had begun to put in place promising structures designed to prevent such spread. Centrally embodied in the Nuclear Nonproliferation Treaty of 1968, which had successfully and amazingly kept the number of nuclear powers, actual as well as admitted, relatively low, that consensus gave primacy to treaty obligations, international cooperation and a serious commitment by existing nuclear powers to move toward ultimate nuclear abolition. All of that has been trashed by Bush. “International law?” he smirked in December 2003. “I better call my lawyer.”

Now indications are that nations all over the globe–Japan, Saudi Arabia, Argentina, Brazil, Australia–have begun re-evaluating their rejections of nukes, and some are positively rushing to acquire them. Iran and North Korea are likely to be only the tip of this radioactive iceberg. Nuclear-armed Pakistan and India are a grim forecast of the future on every continent. And the Bush Administration–by declaring its own nuclear arsenal permanent, by threatening nuclear first-strikes against other nations, by “warehousing” treaty-defused warheads instead of destroying them, by developing a new line of “usable” nukes, by moving to weaponize the “high frontier” of outer space, by doing little to help Russia get rid of its rotting nuclear stockpile, by embracing “preventive war”–is enabling this trend instead of discouraging it. How can this be?

The problem has its roots in a long-term American forgetfulness, going back to the acid fog in which the United States ended World War II. There was never a complete moral reckoning with the harsh momentum of that conflict’s denouement–how American leaders embraced a strategy of terror bombing, slaughtering whole urban populations, and how, finally, they ushered in the atomic age with the attacks on Hiroshima and Nagasaki. Scholars have debated those questions, but politicians have avoided them, and most citizens have pretended they aren’t really questions at all. America’s enduring assumptions about its own moral supremacy, its own altruism, its own exceptionalism, have hardly been punctured by consideration of the possibility that we, too, are capable of grave mistakes, terrible crimes. Such awareness, drawn from a fuller reckoning with days gone by–with August 6 and 9, 1945, above all–would inhibit America’s present claim to moral grandeur, which is simultaneously a claim, of course, to economic and political grandiosity. The indispensable nation must dispense with what went before.

“The past is never dead,” William Faulkner said. “It isn’t even past.” How Americans remember their country’s use of terror bombing affects how they think of terrorism; how they remember the first use of nuclear weapons has profound relevance for how the United States behaves in relation to nuclear weapons today. If the long American embrace of nuclear “mutual assured destruction” is unexamined; if the Pentagon’s treaty-violating rejection of the ideal of eventual nuclear abolition is unquestioned–then the Bush Administration’s embrace of nukes as normal, usable weapons will not seem offensive.

Memory is a political act. Forgetfulness is the handmaiden of tyranny. The Bush Administration is fully committed to maintaining what the historian Marc Trachtenberg calls our “nuclear amnesia” even as the Administration seeks to impose a unilateral structure of control on the world. As it pursues a world-threatening campaign against other people’s weapons of mass destruction, that is, the Bush Administration refuses to confront the moral meaning of America’s own weapons of mass destruction, not to mention their viral character, as other nations seek smaller versions of the American arsenal, if only to deter Bush’s next “preventive” war. The United States’ own arsenal, in other words, remains the primordial cause of the WMD plague.

“Memory,” the novelist Paul Auster has written, is “the space in which a thing happens for the second time.” No one wants the terrible events that came after the rising of the sun on September 11, 2001, to happen for a second time except in the realm of remembrance, leading to understanding and commitment. But all the ways George Bush exploited those events, betraying the memory of those who died in them, must be lifted up and examined again, so that the outrageousness of his political purpose can be felt in its fullness. Exactly how the war on terrorism unfolded; how it bled into the wars against Afghanistan, then Iraq; how American fears were exacerbated by Administration alarms; how civil rights were undermined, treaties broken, alliances abandoned, coarseness embraced–none of this should be forgotten.

Given how they have been so dramatically unfulfilled, Washington’s initial hubristic impulses toward a new imperial dominance should not be forgotten. That the first purpose of the war–Osama “dead or alive”–changed when Al Qaeda proved elusive should not be forgotten. That the early justification for the war against Iraq–Saddam’s weapons of mass destruction–changed when they proved nonexistent should not be forgotten. That in former times the US government behaved as if facts mattered, as if evidence informed policy, should not be forgotten. That Afghanistan and Iraq are a shambles, with thousands dead and hundreds of thousands at risk from disease, disorder and despair, should not be forgotten. That a now-disdainful world gave itself in unbridled love to America on 9/11 should not be forgotten.

Nor, given Bush’s reference, should the most relevant fact about the Crusades be forgotten–that, on their own terms and notwithstanding the romance of history, they were, in the end, an overwhelming failure. The 1096 campaign, the “First Crusade,” finally “succeeded” in 1099, when a remnant army fell upon Jerusalem, slaughtering much of its population. But armies under Saladin reasserted Islamic control in 1187, and subsequent Crusades never succeeded in re-establishing Latin dominance in the Holy Land. The reconquista Crusades reclaimed Spain and Portugal for Christian Europe, but in the process destroyed the glorious Iberian convivencia, a high civilization never to be matched below the Pyrenees again.

Meanwhile, intra-Christian crusades, wars against heresy, only made permanent the East-West split between Latin Catholicism and “schismatic” Eastern Orthodoxy, and made inevitable the eventual break, in the Reformation, between a Protestant north and a Catholic south. The Crusades, one could argue, established basic structures of Western civilization, while undermining the possibility that their grandest ideals would ever be realized.

Will such consequences–new global structures of an American imperium, hollowed-out hopes for a humane and just internationalism–follow in the train of George W. Bush’s crusade? This question will be answered in smaller part by anonymous, ad hoc armies of on-the-ground human beings in foreign lands, many of whom will resist Washington to the death. In larger part, the question will be answered by those privileged to be citizens of the United States. To us falls the ultimate power over the American moral and political agenda. As has never been true of any empire before, because this one is still a democracy, such power belongs to citizens absolutely. If the power is ours, so is the responsibility.