Confronted with fanatical Muslims who seem bent on corroborating the worst accusations against their religion, we in the West seem justified in upholding Samuel Huntington's famous thesis of a "clash of civilizations." From the Danish cartoon controversy to the reaction to the Pope's Regensburg address, we seem to be witnessing a virtually unbridgeable abyss between Western principles and Islamic principles. We believe in free speech, and they don't. We believe in reason and pluralism, and they believe in violence.

This way of portraying the Muslim world, however, suffers from two serious flaws. First, it is tactically foolish. This becomes obvious when we recognize that there is a second clash of civilizations, and it is within the Muslim world. The Muslim world is divided between traditional Muslims and radical Muslims. The traditional Muslims are the majority, but the radical Muslims are an influential minority and their numbers are growing. For the past few decades the radical Muslims have been actively recruiting members from the traditional Muslim population. In some parts of the Muslim world, we have seen the Islamic radicals grow so strong that they are in a position to win elections.

What this means is that no victory is possible in the war against terrorism without stopping the growth of radical Islam. No strategy can work that fails to stem the tide of conversions from traditional Islam to radical Islam. No matter how many Islamic radicals we kill, the strength of radical Islam is undiminished if it is capable of replenishing its numbers with traditional Muslim recruits. Consequently America should make it a central element of its strategy to drive a wedge between traditional Islam and radical Islam. If we can find common ground with traditional Muslims, we can deter them from flocking to the radical camp.

Attacks on the Muslim religion as violent, or attacks on the Prophet Muhammad as a forerunner of Islamic terrorism, are counterproductive because they have the predictable effect of unifying traditional Muslims and radical Muslims. How can traditional Muslims be expected to show any sympathy toward assaults on their most sacred beliefs and the founder of their way of life? Even if true, such accusations should not be made publicly because their effect is likely to strengthen the worst elements in Islam and make terrorism worse.

But is the claim that Islam is inherently violent true? Is Islam, in fact, a religion of the sword that cannot be integrated into a modern world that values reason, tolerance, and pluralism? While Christianity began in defeat, with a Christ on the cross and the early Christians hounded and persecuted, Islam began in victory and conquest. Historically, there is no doubt that the Islamic empire was established by the sword- but so was later Christendom. If I may use the Pope's language, however, this should not be considered a mortal sin. Rome was founded by conquest, as was America. The state of Israel too, to take a more recent example, was founded by the sword.

Islam's origins do not justify the conclusion that it is a religion that makes no provision for tolerance or pluralism. Islam has, from the beginning, made a distinction between conquering land and bringing it under the rule of Islamic law—this is allowed—and forcibly converting people to Islam—this is not allowed. The Koran itself insists that "there is no compulsion in religion." I realize that many people bandy about quotations from the Koran about "slaying the infidels" and so on, but these quotations generally apply only to pagans, not to Jews and Christians. As monotheists, Jews and Christians were allowed to practice their religion in every Islamic empire, from the Abbasid dynasty to the Mongol empire to the Ottomans.

When the Muslims ruled northern India for centuries, they could easily have forced all the Hindus to convert on pain of death, but they didn't. India remains overwhelmingly Hindu, a tribute to Islamic and later British tolerance. In the medieval period, Islamic tolerance contrasts favorably with Christian intolerance. In the fifteenth century, Jews were attending synagogues in Muslim regimes while Christian rulers in Spain gave them three choices: leave the country, convert to Christianity, or be killed! Many Jews fled to Muslim countries where they could continue to practice Judaism. The Pope made no mention of these facts in his Regensburg speech.

Let us remember that Islam has been around since the eighth century, while Islamic terrorism is a phenomenon of the past 25 years. Consequently it is wrong to blame Muhammad, the Koran, or the Muslim religion for something that is clearly a recent phenomenon. The real question to ask is, what is it about Islam today that makes it an incubator of fanaticism and terrorism? Why is it that now, as never before, so many people are willing to kill and be killed in the name of Allah? These are questions I address in my recent book The Enemy At Home.

The Pope seems to have realized his mistake. He hasn't taken back his words, but he has changed his tune. He has subsequently met with prominent Muslim leaders in Turkey and emphasized the common ground between Christianity and Islam. He has called for mutual respect and better understanding between the two religions. Unfortunately there are many people, both on the left and the right, who continue to blame Islam for the sins of Islamic radicalism. These people are not only mistaken, they are strengthening the cause of Bin Laden and his allies and making the war on terrorism harder for us to win.