It would be hard to imagine a place more remote from the violence and turmoil of the Middle East than this quiet cul-de-sac in the southern suburbs of Los Angeles. But as David Sultan opens the front door of his home he glances up and down the street anxiously.

He has good reason to be nervous: ever since Dr Wafa Sultan, his wife, appeared on Al-Jazeera, the Arabic television network, last summer she has been receiving death threats. During that and a second broadcast in February Dr Sultan, who was brought up as a Muslim in Syria, denounced the teachings and practice of Islam as “barbaric” and “medieval”.

“The clash we are witnessing around the world is not a clash of religions, or a clash of civilisations,” the impassioned 47-year-old told Al-Jazeera’s stunned audience across the Arab world. “It is a clash between civilisation and backwardness, between the civilised and the primitive, between barbarity and rationality. It is a clash between human rights on the one hand and the violation of these rights on the other, between those who treat women like beasts and those who treat them like human beings.”

The broadcasts have caused an unholy stir in the Muslim world and virtually overnight have turned Sultan, previously known only to a few for her writings on www.annaqed.com, a small Arab-American website, into one of the most controversial figures in the international debate about Islam. The broadcasts have been downloaded more than 1m times from the internet and she has been interviewed on CNN and profiled by The New York Times and Le Monde.

While some acclaim her as “a voice of reason” others have denounced her as a “heretic” and insist that she deserves to die. What seems to have most infuriated many Muslims were Sultan’s comparisons between how Jews and Muslims have coped with the tragedies that have befallen them.

“The Jews have come from tragedy and forced the world to respect them,” she said, “with their knowledge, not with their terror; with their work, not with their crying and yelling.

“We have not seen a single Jew blow himself up in a German restaurant. We have not seen a single Jew destroy a church. We have not seen a single Jew protest by killing people. Only the Muslims defend their beliefs by burning down churches, killing people and destroying embassies. The Muslims must ask themselves what they can do for humankind, before they demand that humankind respect them.”

Sitting in the airy living room of the spacious modern home where Sultan and her husband live, it is hard to believe this small, neatly dressed woman could be at the centre of an international firestorm. Just as improbable is that the most important and controversial critics of Islamic fundamentalism, violence and intolerance are, like Sultan, women, mostly from Islamic countries.