On a Saudi Arabian airline flight out of Amman, Jordan, bound for Riyadh, I get my first hint of Saudi extremes.

The in-flight movie channel showing an American sitcom has been digitized. Women's necklines are blurred to conform with the conservative views of Saudi religious police.

On the next channel, there's an old movie showing the English and French fighting on horseback in the 14th century. The religious police have digitized the arms of French soldiers. Above their swords, the uniforms bear a Catholic cross, which I suppose somehow offends Saudi religious sensibilities.

This is after all the country which allows no churches, no synagogues, nothing but mosques. Religious tolerance is something the Saudis have failed to preach, an omission that may now threaten the existence of the state.

We have come to Riyadh, capital of Saudi Arabia, to report on the growing violence against Westerners. The kidnapping and killing of American contract worker Paul Johnson (search) in June capped a year-long string of attacks on Western compounds, including American homes and oil offices, resulting in the deaths of more than 80 people and the wounding of hundreds.

Foreign television crews have never been allowed to easily report from Saudi Arabia, and the recent Al Qaeda attack on a BBC television team has made things even more difficult.

According to the Ministry of Information minder who meets us at the airport and escorts us everywhere, the BBC crew was filming in a "nasty part of town" when it was "randomly attacked." Al Qaeda gunmen opened fire with machine guns, killing the cameraman and severely wounding the reporter.

Our Ministry of Information driver just happens to be the same one who was with the BBC crew that day. He explains in Arabic: "There were in fact four cars used by Al Qaeda, each with two militants inside involved in the attack."

A FOX security consultant notes, "Four cars, two-man teams — that was no random attack." Al Qaeda is well organized.

"It's all been a frightening wake-up call the Saudis have suddenly had to deal with," explains an American diplomatic source here.

Even after Sept. 11 — in fact, up until a year ago — the Saudis paid only lip service to American calls for cooperation in the fight against terrorism. Only recently have they started to take the threat from Al Qaeda seriously because violence has come to Saudi Arabia itself.

U.S. sources say the Saudis have overhauled their interior ministry, changing it from a crime-fighting bureau to an anti-terror task force.

"They understand Al Qaeda ultimately has set its sights on overthrowing the Saudi royal family," says the U.S. diplomat.

By attacking Westerners, the backbone of the skilled labor force in the kingdom, Al Qaeda hopes to destabilize the rule of the al-Saud family and sow the seeds of a revolution, say some analysts.

It's impossible to quote most Saudi intellectuals, who fear being jailed for speaking out.

One leading Saudi political scientist told me this week, "Please don't use my name. The Interior Ministry is now busy classifying people. You are either with the royal family or against it, and if we speak out we risk being labeled as a threat."

He goes on to say Al Qaeda means to carry out its not-so-quiet revolution here with a simple but daunting philosophy: Win, or die trying.

Friday prayers outside a Riyadh mosque reveal a few important things.

First, as we are chased off by uniformed police and threatened with arrest for even being near a mosque, it's clear Westerners are not welcome in many parts of town. It has become more dangerous for us, not less, despite a crackdown against extremists by the overhauled Interior Ministry.

But we are there long enough to also hear a more moderate message from imams in Saudi Arabia, some of whom were known in the past to have railed against America or the West and spoken often about jihad.

Our Ministry of Information minder explains that in the last year, imams have been "re-educated" to deliver moderate messages. That means no talk of jihad is allowed. Summer camps run by religious teachers, normally used as recruiting centers for extremists, have been canceled.

Our U.S. diplomatic source says the Saudis are really trying to stop Al Qaeda dead in its tracks.

"There is a lot going on you don't hear about," the diplomat says. "FBI agents have been given access to forensic evidence at crime scenes in Riyadh, and the U.S. will start training Saudi anti-terror teams."

Our sources also say FBI agents were taken to a Riyadh house where Paul Johnson was likely held and murdered. (His body has yet to be found.) It's unprecedented cooperation because of an unprecedented threat to the Saudi kingdom.

In the meantime, most Americans are leaving. Sources say American expatriate workers, who used to number at least 50,000, now add up to something below 30,000. Surrounded by concrete walls, locked inside "expat" compounds, most don't dare go out anymore. Their security advisers advise them not to talk to reporters.

At the Jedawal compound (search), which houses, among others, the American mechanics who service the Saudis' F-15 fighter aircraft, the local security chief explains it's because "raising their profiles could get them killed."

But some expats who have left the compound tell me it's also because some Americans believe security in the compound has been less than perfect, and that no one wants that secret out.

At Jedawal, for instance, rumors persist that some third-country employees manning the gates and other sensitive areas have gone unpaid for months.

"Could this make is easier for Al Qaeda to get someone on the inside? We think that may have happened in last year's attack on three compounds in Riyadh, including Jedawal," says one former American resident.

Former resident Bruce Pawlowski and his wife Barbara left Saudi Arabia last month saying they were forced out of Jedawal for repeatedly raising objections to what they describe as "lax security."

"We were continually concerned about the security, both within the compound and on the outside, [and] with the people guarding it," says Bruce Pawlowski. He was asked to leave, he says, because by raising the issue with the American Embassy, "that caused the Saudis to lose face that they weren't doing their job properly."

Barbara Pawlowski says she has heard at least half the Americans living in the Jedawal compound have either left or are in the process of leaving. The Jedawal security manager refused to allow FOX News onto the compound, and wouldn't speak to us on camera.

This week there are more security warnings. There is "traffic," says one security man, that Al Qaeda is getting ready to carry out another kidnapping or attack on a compound.

We are warned we also may be tracked and targeted as foreign journalists by Al Qaeda.

But today I keep thinking about that in-flight movie, with the blurred necklines and Western religious symbols.

I know it's partially about religious conservatism in a Muslim country, but I also wonder if it's a symbol of how the Saudis have never taught tolerance of outside values, whether they be women's fashion or another's religion.

A new investigative report posted on the Web site of the Saudi Institute (search), a Washington-based dissident group, states that despite supposed school reforms in the kingdom after Sept. 11, children at a Saudi-run Islamic school in the Virginia suburbs are still being taught to disparage Judaism and Christianity.

A textbook for 6-year-olds published last year by the Saudi education ministry, and currently in use at the Virginia school, reads: "All religions other than Islam are false." A note for teachers says they should "ensure to explain" this point.

The Saudi political scientist says "It seems we are now reaping the bitter crop of a generation that was taught jihad by the religious zealots who hate the West and now equally threaten the nation of their birth, Saudi Arabia."