To understand what Americans are fighting, it is necessary to first understand that we are not fighting a "War on Terror." We are no more fighting a "War on Terror" than we fought a "War on Kamikazes" in World War II. Of course we had to stop Kamikaze attacks, the suicide crashing by Japanese pilots of airplanes into American war ships. But we were fighting Japanese fascism and imperialism.

The same holds true today. We are fighting Islamic fascism and imperialism (though surely not all Muslims).

The parallels are almost as extensive as any historic parallels of two different phenomena can be. The fascist Japanese regime aimed to subjugate much of the world, Asia in particular, and it used whatever violence it could think of without any moral constraints. The fascist element within Islam wishes to subjugate the entire world using whatever violence it can think of without any moral constraints.

Of course, there are differences: Imperial Japan was preoccupied with dominating Asia, while imperialist Islam aims to dominate the whole world. And imperial Japan did so as an outgrowth of nationalism, while imperialist Islam does so from an outgrowth of a trans-national religious ideology.

Islamic terror is a tactic of an ideology. That ideology can be called "radical Islam," "militant Islam" or "Islamist," but it is rooted in Islamic imperialism.

With a background in religious studies and having studied Arabic and Islam, many listeners have called my radio show asking me if I consider Islam to be inherently violent or even evil. From 9-11 to now, I have responded that I do not assess religions; I assess the practitioners of religions. Why? Because it is almost impossible to assess any religion since its own adherents so often differ as to what it is. For example, is Christianity the Christianity of most evangelicals or that of the National Council of Churches? On virtually every important moral issue, they differ. The same holds true for right- and left-wing groups within Judaism.

Nevertheless, one can say that from its inception, Islam has been imperialist. My working definition of imperialism is that of University of London professor Efraim Karsh, whose recent book, "Islamic Imperialism" (Yale University Press), is one of the few indispensable books on Islam.

Karsh defines imperialism as "conquering foreign lands and subjugating their populations." Whenever possible, Muslims from the time of Muhammad have done that. Now, the Church also subjugated peoples to Christianity, and Europe suffered from prolonged religious wars. But as Karsh notes, from its inception, Christianity acknowledged a separation of the religious and the political, rendering to Caesar what is Caesar's and to God what is God's.

No such division was allowed for in Islam. That is why the nation-state developed in the Christian world but not in the Muslim world. The Muslim states of the Middle East, for example, are creations of Western (secular) imperialism or pre-date Islam (Egypt, for example); and they are foreign concepts to most Middle Eastern Muslims, who recognize themselves much more as part of the ummah, the Muslim community, than as Iraqis, Jordanians, Syrians, etc.

Nor is Islamic imperialism only a function of Muslim behavior rather than Muslim theology. Karsh opens his book citing the statements of four Muslim figures.

The Prophet Muhammad in his farewell address: "I was ordered to fight all men until they say, 'There is no god but Allah.'"

Saladin (great 12th-century founder of the Ayyubid dynasty that included Ayyubid Egypt, Syria, Yemen, Iraq and much of present-day Saudi Arabia): "I shall cross this sea to their islands to pursue them until there remains no one on the face of the earth who does not acknowledge Allah."

Ayatollah Ruhollah Khomeini (father of the Islamic revolution in Iran): "We will export our revolution throughout the world . . . until the calls 'There is no god but Allah and Muhammad is the messenger of Allah' are echoed all over the world."

Osama bin Laden in November 2001: "I was ordered to fight the people until they say 'there is no god but Allah, and his prophet Muhammad.'"

No one should have a problem with Muslims wanting the whole world Muslim. After all, Christians would like the whole world to come to Christ. What should matter to all people is the answer to one question: What are you prepared to do to bring the world to your religion? For virtually every living Christian, the answer is through modeling and verbal persuasion (and Jews never believed the world needs to be Jewish).

But by the most conservative estimates, 10 percent of Muslims are in sympathy with the bin Laden way. That means at least 100 million people are prepared to murder (and apparently torture) in Allah's name. And given the history of Islamic imperialism and its roots in Muslim theology, hundreds of millions more are probably fellow travelers. Hence the almost unanimous Muslim governments' support for the genocidal Islamic regime in Sudan.

We pray that there arises a strong Muslim group that is guided by the Quranic verse, "There shall be no coercion in matters of faith."

But until such time, we had better understand that we are not merely fighting a war on terror, but a war against an ideology that wishes us to convert, be subject to Islamic law, or die.