Ayman al-Zawahri, al-Qaida's No. 2 man, last month announced that Americans must choose: Convert to Islam or continue to receive acts of terror.
Al-Zawahri was reiterating a fundamental concept of Salafi Islamic teaching, the fountainhead of extremist thinking. Yet the authors of the American government's recent intelligence report on terrorism's spread seem not to have been listening.
Zawahri's threat is based on a saying of the Prophet Muhammad as written in Sahih Al-Buchary, a central book of Salafi Islamic teaching. This hadith, or fundamental concept, states: "I have been ordered by Allah to fight and kill all mankind until they say, 'No God except Allah and Muhammad is the prophet of Allah' (Hadith Sahih)."
Based on this hadith, early Muslims used the sword to spread Islam throughout the world. The same hadith inspires contemporary Islamic terror including this summer's thwarted London airplane explosions. Other rationales that terrorists use to justify terrorism - the Arab-Israeli conflict, America's involvement in Iraq - are simply useful propaganda cover stories, not the actual causes or goals of terrorists' actions.
Americans must be wary of political leaders who accept the propaganda explanations. To win the war on terror, America's leaders must recognize the powerful role of the Islamic religious principle of jihad, Islam's belief that it must conquer the world, which derives from the above hadith. Belief in jihad is what causes so many Muslims worldwide to cheer terrorist acts such as 9/11, European subway bombings, and Hezbollah and Hamas attacks against Israel.
Allowing jihadist teaching to continue is like allowing cancer cells to survive in a human body.
The human immune system demonstrates that nurturing normal cells and respecting their variance sustains life. A healthy body nourishes cell diversity. A healthy body politic, similarly, must value respect for different beliefs. At the same time, if an immune system shows any tolerance whatsoever for cancer cells, the latter will terminate that body's life. The immune system of a body politic must have a similar zero tolerance for beliefs that incite violence against its citizens.
Cancer can be overcome if an individual has a strong immune system that acts to triumph over the killer cells. Similarly, the cancerous teachings of Salafi Islam could become insignificant if the majority of Muslims were to vocally oppose them.
Unfortunately, however, the vast majority of Muslims, Islamic organizations and Islamic scholars have not publicly objected to these teachings. There have been no powerful Muslim demonstrations to denounce Osama bin Laden and not a single fatwa by top Islamic scholars or organizations to consider bin Laden an apostate - as was done to Salman Rushdie just for writing a novel.
Because the teachings continue, a significant proportion of the world's Muslims have become passive terrorists, peaceful citizens whose sympathy in their hearts and support with their purses enable terrorism's spread.
If Islamic scholars and organizations in America disapprove of jihadist teachings, they must speak out against them. Americans should consider Muslims to be moderates, and Islam a peaceful faith, only if, in English and in Arabic, Muslims clearly denounce their violent hadiths and strike them from the books that educate their next generation.
In addition to internal immune reactions, externally applied interventions also can destroy cancer cells. Like cancer-fighting chemotherapy, strongly applied military might can reduce large tumors. America eliminated al-Qaida training camps in Afghanistan, but the verdict is not yet in on whether Israel this past summer similarly decimated Hezbollah.
To conquer the metastases of extremist Islam, however, words may be the most potent weapons. Outspoken condemnation of the theological sources of terrorism by American intellectuals and politicians, reinforcing the self-examination of Muslims themselves, could make a vital difference.
Addressing the theological wellsprings of Islamic terrorist motivation is essential if America is to succeed in its war against terrorism. Pope Benedict XVI has begun leading the way. Neither political correctness nor Muslim outrage must be allowed to prevent further realistic talk about the religious underpinnings of Islamic violence. Otherwise Islamic teaching will continue to spread jihad's cancerous beliefs.
Dr. Tawfik Hamid, an Egyptian physician, Islamic scholar and former extremist, is the author of The Roots of Jihad (www.rootsofjihad.org).