What steps should Western border agencies take to defend their homelands from harm by Islamists?

In the case of non-citizens, the answer is simple: Don't let Islamists in. Exclude not just potential terrorists but also anyone who supports the totalitarian goals of radical Islam. Just as civilized countries did not welcome fascists in the early 1940s (or communists a decade later), they need not welcome Islamists today.

But what about one's own citizens who cross the border? They could be leaving to fight for the Taliban or returning from a course on terrorism techniques. Or perhaps they studied with enemies of the West who incited them to sabotage or sedition. Clearly, the authorities should take steps to find out more about their activities, especially given the dangerous jihadi culture already in place in many Western countries, including Canada.

This question arose in late December 2004, after a three-day Islamist conference,"Reviving the Islamic Spirit," took place in Toronto. The event, boasting a host of high-profile Islamist speakers such as Bilal Philips, Zaid Shakir, Siraj Wahhaj, and Hamza Yusuf, alarmed the U.S. Customs and Border Protection (CBP), America's new border agency.

Spokeswoman Kristie Clemens explained that her agency had information on how events such as the one in Toronto"may be used by terrorist organizations to promote terrorist activities, which includes traveling and fund raising." Ms. Clemens later added that the CBP has" credible, ongoing information that these types of conferences have been used and are being used by terrorist organizations to not only transport fraudulent documents but to mask travel by terrorists." Terrorists imagine, she pointed out, that if they travel in a large group,"we're going to be less restrictive and try to expedite the processing."

Her explanation hints at why the CBP decided to detain nearly 40 Muslims, many of them American citizens, as they returned to the U.S. by car from the Toronto conference. The travelers report they spent long hours at the border near Buffalo, N.Y., and none too pleasantly. One woman said she was asked whether the wire in her underwire bra was a weapon. Another, seven months' pregnant, reported that border agents lifted her blouse to make sure she really was pregnant. A third traveler quotes himself asking a border guard,"If I refuse to give my fingerprints, what will you do?" to which he got a terse reply:"You can refuse, but you'll be here until you do."

When Daniel W. Sutherland, officer for civil rights and civil liberties at the Department of Homeland Security, the CBP's parent organization, spoke in Buffalo earlier this month, he discussed the December episode. On principle, however, he neither justified nor condemned CBP's procedures. Rather, he only acknowledged that CBP did an"after-action review" and refined a few points. Mr. Sutherland placed the detaining of citizens into a larger context ("There are multiple pieces to that puzzle") and spent most of his time emphasizing the need for his department and Muslim groups to work better together.

He was right to remain discreetly uninformative. America finds itself at war with radical Islam not just in Afghanistan but in Buffalo, Boston, Boca Raton, and Baltimore. Controlling the border flow, therefore, has paramount importance. As a law enforcement agency, the CBP in this and other cases (notably that of Tariq Ramadan) should not divulge its exact reasons for excluding foreigners or detaining citizens. To do otherwise would compromise national security.

Which in turn probably explains why, last week, the Council on American-Islamic Relations and the American Civil Liberties Union – two organizations consistently hostile to American self-protection – goaded five of the detained travelers to sue the federal government on the grounds that they"were unlawfully detained, interrogated, fingerprinted, and photographed."

Two of the plaintiffs' demands have lasting implications: that the court declare the CBP had violated the travelers' rights and that it enjoin the CBP from"detaining, interrogating, fingerprinting, and photographing United States citizens who are Muslim because they are returning to the country after having attended religious conferences."

Were the plaintiffs to prevail in this case, attending religious conferences would instantly become the favored method for terrorists and other Islamists to cross the American border without hindrance. Such a malign implication means this lawsuit needs to be tossed out by the courts.

This article is reprinted with permission by Daniel Pipes. This article first appeared in the New York Sun.