Three Muslim students approached me after I had finished a speech at Harvard University. I was there to talk about the threat of radical Islam across the globe, as part of the Ethics and Public Policy Center's Program to Protect America's Freedom.

The students, one man and two women, wore Western-style clothes and spoke English with little or no accent. They disputed my description of Islam as it's practiced in the Middle East, maintaining that al-Qaeda's version of Islam in no way reflects the Islam that is practiced around the world.

So I asked them a question: Should apostates - Muslims who convert to another religion - be subject to execution?

One of the women quickly said no. She insisted that she was free to leave Islam if she wanted to, and that she knew other people who had done so without a problem - in the United States.

I said I wasn't talking about her and others' freedom of religion in this country. What if they lived in a Muslim-majority country?

Silence. Eventually, the young man blurted out, "That's different."

Why? I asked. I recall him saying, "Because in Muslim countries, Islam and the government are one, and converting from Islam is the equivalent of treason against the government, punishable by death." The two women agreed.

I suspect that most readers will find it shocking that three liberal, Western Muslims at Harvard expressed this view. But what's shocking is that anyone finds this shocking.

If, after 9/11, the U.S. government had set out to clearly define the nature and gravity of the Islamist threat we face, it would be common knowledge that the views of these three Harvard students are widely held in the Muslim world.

However, President George W. Bush insisted on calling it a "war on terror." That was a mistake. Terror is a tactic, not an ideology like fascism or communism. As such, our leaders continue to mislead about the reality and complexity of the war in which we are engaged.

While many so-called moderate Muslims oppose al-Qaeda's tactics, they nevertheless support global expansion of Islam. They embrace the imposition of Islamic sharia law on people of all faiths in Muslim countries - a law that requires such things as unequal treatment of the sexes and the killing of gays and apostates.

Why do so many Muslims still hold these views in the 21st century, even in the West? Partly because prominent Islamic authorities have failed to chart a different course.

But that may be changing. Mohammed Sayyed Tantawi, the grand sheikh of al-Azhar, a prominent university in Cairo, Egypt, seems recently to have endorsed a more liberal attitude toward apostasy. According to Tantawi, a Muslim who renounces his faith should be left alone as long as he does not threaten or belittle Islam. Giving up the faith alone should not trigger actions against an apostate in this view; only acting as an enemy of Islam should prompt reprisals.

It's not American religious freedom, but it's a start.

In addition, Tantawi has said it is permissible for Muslims to donate money for the construction of Christian churches. He even publicly rebuked Muslims who argue that "building churches is a sort of sin."

Recently, the sheikh visited a school in Cairo and expressed anger at a young girl for wearing a niqab, a veil that covers the entire face, with only a slit for the eyes. "The niqab is a tradition; it has no connection with religion," Tantawi told the girl, and he asked that she remove it. He also said he would issue a fatwa banning girls who wear the niqab from attending al-Azhar institutions.

Also promising is an October report by a group of Muslim scholars and activists in the United Kingdom, "Contextualizing Islam in Britain: Exploratory Perspective." Its most significant points are: "Since Islam is a coherent and universal religion, the principle of religious freedom should apply across the world, and not just in Britain"; and "It is important to say quite simply that people have the freedom to enter the Islamic faith and the freedom to leave it."

It is certainly not the place of non-Muslims to say what constitutes authentic Islam. But if leading Muslim clerics are prepared to take on al-Qaeda's interpretation of Islam in this war of ideas, our leaders and our media should publicize their work and extol their courage.

Rick Santorum is a Senior Fellow at the Ethics and Public Policy Center and former U.S. Senator (R-PA).