[Mr. Pipes is the director of the Middle East Forum. His website address is http://www.danielpipes.org. Click here for his HNN blog.]

Estimating how many potential terrorists reside in one's country is a highly inexact business, but there's a striking correlation between a British government report recently leaked to London's Times and a new opinion survey commissioned by the Daily Telegraph.

Drawing on unidentified"intelligence," the government report (analyzed by me at"The Next London Bombing") finds as many as 16,000"British Muslims actively engaged in terrorist activity."

Then, using standard survey research methods, the reputable YouGov polling firm interviewed 526 Muslim adults across Great Britain online during July 15-22, weighing the data to reflect the British Muslim population's age, gender, and countries of origin. The survey found that 1 percent of them, or"about 16,000 individuals, declare themselves willing, possibly even eager, to embrace violence" in the effort to bring an end to"decadent and immoral" Western society.

Should their ranks really be so thick, such a huge number of potential terrorists could cause an unprecedented security crisis for Britain, with all the attendant economic, social, political, and cultural ramifications one can imagine.

The YouGov survey contains many other statistics that should interest, if not shock, Britons and other Westerners.

• Muslims who see the 7/7 bombing attacks in London as justified on balance: 6 percent.
• Who feel sympathy for the"feelings and motives" of those who carried out the 7/7 attacks: 24 percent.
• Understand"why some people behave in that way": 56 percent.
• Disagree with Tony Blair's description of the ideology of the London bombers as"perverted and poisonous": 26 percent.
• Feel not loyal towards Britain: 16 percent.
• Agree that"Western society is decadent and immoral and that Muslims should seek to bring it to an end": 32 percent willing to use non-violent means and (as noted above) 1 percent willing to use violence"if necessary." Just 56 percent of Muslims agree with the statement that"Western society may not be perfect but Muslims should live with it and not seek to bring it to an end."
• Agree that"British political leaders don't mean it when they talk about equality. They regard the lives of white British people as more valuable than the lives of British Muslims": 52 percent.
• Dismiss political party leaders as insincere when saying"they respect Islam and want to co-operate with Britain's Muslim communities": 50 percent.
• Doubt that anyone charged with and tried for the 7/7 attacks would receive a fair trial: 44 percent.
• Would not inform on a Muslim religious leader"trying to 'radicalise' young Muslims by preaching hatred against the West": 10 percent.
• Do not think people have a duty to go to the police if they"see something in the community that makes them feel suspicious": 14 percent.
• Believe other Muslims would be reluctant to go to the police"about anything they see that makes them suspicious": 41 percent.
• Would inform the police if they believed they knew about the possible planning of a terrorist attack: 73 percent. (In this case, the Daily Telegraph did not make available the negative percentage.)

Another opinion poll, this one commissioned by Sky News and carried out by Communicate Research (which interviewed 462 UK-based Muslims by telephone) found similar results:

• Muslims who agree with what the London suicide bombers did: 2 percent.
• Who believe there is a Koranic justification for the bombings: 5 percent.
• Disagree with the statement that"Muslim clerics who preach violence against the West are out of touch with mainstream Muslim opinion": 46 percent.
• Think of themselves as Muslim first and British second: 46 percent. Another 42 percent do not differentiate between the identities. A mere 12 percent see themselves as British first and Muslim second.

Comments: (1) It is hard to say which is the most alarming of these many worrisome statistics, but two stand out. That less than three-quarters of Muslims in Britain indicate they would tell the police about an impending terrorist attack raises grave doubts about the Blair government's tactic of getting Muslims to police their own community. That one-third of Muslims do not accept British society and want to end it, presumably to pave the way for an Islamic order, casts comparable doubts on Britain's much-vaunted multicultural ideal.

(2) Even the Telegraph's interpreter of its survey, Professor Anthony King of Essex University, feels compelled to sugar the results, calling them"at once reassuring and disturbing, in some ways even alarming," whatever that means. In several specific instances, he turns hair-raising statistics into cheerful ones (that 73 percent would warn of an impending terrorist attack he deems"impressive"). The newspaper's and the professor's panglossian attitude makes one wonder what might wake the British to the Islamist hell growing in their midst.