If you are an American, raised on a diet of Western rationalism, it is difficult to understand the idea of holy war. We can look back hundreds of years to the Wars of Religion, where Christians rapaciously killed each other over matters of faith. We can look at Northern Ireland’s troubles and glimpse, just barely, divinely sanctioned warfare. We can of course look back to communism and fascism—the West’s most recent attempts to bring heaven to earth—and better appreciate the ideological fire that produces a moral imperative to kill women and children.

Yet we always want to avert our eyes from such burning light and believe that there must be accessible solutions to abate the anger of two opposing sides. The liberal in us wants to believe that humanity is bound by hope. The pragmatist inside never stops searching for some deal that will allow the avaricious and sybaritic side of human nature to triumph over messy, abstract idealism. The pacifist in our hearts doesn’t want to believe that people can see violence as an expression of fraternity and love.

On September 11 American rationalism got fuel-bombed by a force whose mores are hopelessly irreconcilable with our own. For Usama bin Laden, the Saudi holy warrior, and for the true-believers who converted civilian airliners into missiles, the hand of God really did take down the World Trade Center’s twin towers. This is an obvious point that bears repeating, since, as we seriously start thinking about how we are going to reply to this horrendous assault, American rationalism is likely to reenter the debate.

In Western Europe and Canada, very neat, tidy places, we can already see what’s brewing. The call to search for "the roots of this problem"—which inevitably implies that we have done something wrong, and until that something has been corrected we can expect others to be mean-spirit-ed—will no doubt return, at least on the left-hand side of America. We can confidently expect that Israel will somehow be blamed for this mess, since the Israeli-Arab confrontation, so the State Department has always told us, is obviously the epicenter of the anti-American hostility throughout the Middle East. (This is, of course, news to Usama bin Laden, as it is to Ayatollah Khomeini’s faithful followers, who don’t seem to think that five million Jews in Israel have sufficient stature to be the "Great Satan" in their battle between Good and Evil.) We can certainly expect guilt and anxiety to return to the op-ed pages as soon as America starts to punish bloodily those responsible in the Middle East. Holy wars are exceptionally ugly because they offer no escape from a guerre à outrance—even if only one side believes that God is at their backs.

And this is definitely a fight to the bitter end, which means first and foremost that we must eliminate Usama bin Laden. As long as he lives, we have lost the war against radical Islamic terrorism. He will never stop bombing us. His magnetism within militant Islamic circles is undeniable. He will never stop recruiting others to the cause. He has made a rag-tag outfit of Islamic militants, his terrorist umbrella organization Al Qaeda, in just a few years the most celebrated holy warriors in modern Islamic history.

Bin Laden didn’t do this, of course, all by himself: He has in all probability received critical assistance from other terrorist organizations and Middle Eastern states. The bombings in New York and Washington may well confirm what the attack on the USS Cole in Aden, Yemen, strongly suggested—that either or both the Hezbollah of Lebanon (which means the ruling clergy of the Islamic Republic of Iran) and Saddam Hussein helped accelerate the learning curve of bin Laden’s kamikazes.