Saudi Arabian Airlines declares on its English-language Web site that the kingdom bans “Bibles, crucifixes, statues, carvings, items with religious symbols such as the Star of David.” Until the Saudi government changes this detestable policy, its airline should be disallowed from flying into Western airports.

Michael Freund brought this regulation to international attention in an August 8 Jerusalem Post article, “Saudis might take Bibles from tourists,” in which he points out that a section on the Saudia Web site, “Customs Regulations,” lists the forbidden articles under the rubric “Items and articles belonging to religions other than Islam.”

Mr. Freund followed up by calling the Saudia office in New York, where an employee identified only as “Gladys” confirmed that this rule really is applied: “Yes, sir, that is what we have heard, that it is a problem to bring these things into Saudi Arabia, so you cannot do it.” An unnamed official at the Saudi consulate in New York further confirmed the regulation: “You are not allowed to bring that stuff into the kingdom. If you do, they will take it away. If it is really important to you, then you can try to bring it and just see what happens, but I don’t recommend that you do so.”

Responding to the Saudi ban on churches and Bibles and Stars of David, some would ban mosques, Korans, and crescent moons in the West, but that is clearly untenable and unenforceable, given the freedoms of speech and worship. The Koran, for example, is not a Saudi artifact and cannot be held hostage to Saudi policies. However closely it identifies with Islam, the Saudi government does not own the religion.

Further, as Stephen Schwartz of the Center for Islamic Pluralism points out, signs in Saudi airports warn Muslim travelers that the airport’s mutawwa’in, or religious police, confiscate Korans, other Islamic literature, and Muslim objects of non-Saudi origin. While discriminating specifically against Shiites and Ahmadis, this policy manifests a wider insistence on Wahhabi supremacism. More broadly, the Saudi leadership runs a country that the American government has condemned repeatedly as having “no religious freedom” and being among the most religiously repressive in the world.

Saudia, the state-owned national carrier and its portal to the world, offers a pressure point for change. To take advantage of this vulnerability, Western governments should demand that unless the Saudi government at least permits “that stuff” in, Saudia faces exclusion from the 18 airports it presently services in Europe, North America, and Japan. If those routes are shut down, Riyadh will face a tough choice:

• Ignore this action: Allowing Western airlines to service Saudi Arabia without reciprocity would presumably be too great a humiliation for the monarchy to abide.

• Cut off the Western airlines in return: Cutting off the Western airlines would unacceptably isolate Saudis from major markets and premier destinations.

• Permit non-Wahhabi religious items: That leaves the Saudis no choice but to accept the import of “Bibles, crucifixes, statues, carvings, items with religious symbols such as the Star of David.” Further, once these materials are allowed, other benefits would likely follow, such as permitting non-Islamic religious buildings and services in the kingdom for the millions of non-Muslims who live there. Muslims who reject the Wahhabi interpretation of Islam would also eventually benefit from this loosening.

Such joint action also sends a long-overdue signal to the despots of Riyadh — that Westerners have thrown off their servile obeisance to their writ. Who will be first to act? Which national government or municipality will arise from the customary dhimmi posture and ban Saudia (slogan: “We aim to please you”) from its runways, thereby compelling the kingdom to permit infidel religious items, monotheistic and polytheistic alike, into its territory? Where are you Athens, Frankfurt, Geneva, Houston, London, Madrid, Málaga, Manchester, Milan, Munich, New York, Nice, Osaka, Paris, Prague, Rome, Vienna, and Washington, D.C.?

If no government acts, what about a delegation of Christians, Jews, Hindus, Buddhists, and others boarding a Saudia flight with much publicity, openly displaying their religious artifacts, daring the airline to confiscate them? Or which public service law firm in those 11 countries will bring local human rights suits against Saudia as an arm of the Saudi government?

This issue provides an opportunity for left and right to unite against radical Islam. Who will take the lead to confront Saudi discrimination, arrogance, and repression?

Mr. Pipes (www.DanielPipes.org) is the director of the Middle East Forum.