JIDDA, Saudi Arabia — A professor at King Abdulaziz University was giving a lesson last month on politics and activism, terrorism and tolerance. The recent killing of Egyptian secularist author Farag Foda by Islamic extremists came up.

"I said, 'It's one thing for Palestinians to kill Jews, or even for Palestinians to kill Arab collaborators, but Egyptians killing Egyptians? How can you justify the killing of Farag Foda?' " he recalled. "One student raised his hand and said, 'He wrote an article criticizing Islam. He is an infidel.' "

Afterward, the student came to his office, and the young man's voice was quiet but firm. He wanted to know why the professor wasn't defending Islam, why the professor didn't side with the men who had gunned down Foda: men, the young man said, who were \o7 montazemeen\f7 --determined in the path of religion.

"Before this happened, I was ready to be objective," the professor said. "Now, that is finished. These people, they are so goddamned dangerous. To them, if you study in the U.S., you are secular. You let your wife uncover her face, you are secular. Really, in these times, we are wrong people in a wrong place."

This is Jidda, the most cosmopolitan city in a country that is America's staunchest ally in the Persian Gulf. But in the months since U.S. troops left Saudi Arabia, a period when the secretive desert kingdom has been largely shielded from the view of the world, a growing current of religious radicalism has swept the country, challenging Saudi Arabia's moves for political and social connections with the West, demanding political reform and even raising unprecedented questions about the House of Saud's right to govern in the land of Islam's holiest cities.

While Saudi Arabia has always been a bastion of religious conservatism, governed by a historic coalition between the Saudi Royal Family and Islam's conservative Wahhabi sect, it has been a marriage of convenience that has also permitted the kingdom to forge strong ties with the West and to implement modern industrial and economic networks.

Now, a new breed of radical young intellectuals is challenging the Saudi government's true commitment to Islam. These powerful new Islamicists, with strong philosophical allegiance to Muslim leaders in Sudan and North Africa, are signing petitions to King Fahd and distributing volatile underground audiocassette tapes that demand greater public participation in government, the dismantling of Saudi Arabia's Western-oriented banking system and an end to the kingdom's peace overtures with Israel and its strong political interdependence with the United States and Europe.