The naturalized citizen swears to “support and defend the Constitution and laws of the United States of America against all enemies, foreign and domestic…bear true faith and allegiance to the same…[and] bear arms on behalf of the United States when required by the law.” Naturalized citizens tie their own destiny to the destiny of this society, not their former one, for better or worse. So the potential bomber takes an oath to defend the Constitution and the U.S. against all enemies, while committed in his heart to a radically different political order.

The challenge that this would-be bomber poses for us is not to change our foreign policy or improve economic conditions in the Muslim world. We already do that. The challenge is to uncover the deceit of such phony citizens.

One measure employed during the Cold War was to question prospective citizens about whether they had ever been members of the Communist Party, a recognition that communism was an ideology fundamentally hostile to the American way of life. That question about the Communist Party is still asked today, even though the threat posed by communism has receded to a few desperate holdouts. I was surprised to encounter it not once but twice during my own application process. And it got me thinking: Is it not time to update the application form, substituting political Islam for Communism?

Of course, the question alone would do nothing to uncover deceit on the part of a determined terrorist. But it would establish the principle that adherence to political Islam, with its dreams of a society ruled by Shariah (not to mention a world ruled by a restored caliphate), is incompatible with the terms of the oath of allegiance.