Whence comes the main danger to homeland security in North America and Western Europe? With the exception of the Oklahoma City bombing of 1995, notes Al-Qaeda authority Rohan Gunaratna, all major terrorist attacks of the past decade in the West have been carried out by immigrants. A closer look finds that these were not just any immigrants but invariably from a specific background: Of the 212 suspected and convicted terrorist perpetrators during 1993-2003, 86% were Muslim immigrants and …showed first 75 words of 704 total…

…showed last 75 words of 704 total…sleepers and hit squads while allowing normal business and pleasure travel should be a priority for Washington and Ottawa. For Americans, adjusting the Visa Waiver Program and controlling land borders with Canada and Mexico are higher priorities than worrying about Iranians and Syrians. Mr. Leiken's research guides Westerners to real homeland security. But achieving this will be a challenge, for acknowledging the European Islamist source of violence means giving up today's easy reliance on euphemisms.