Pentaerythritol tetranitrate (PETN), the explosive Umar Farouk Abdulmutallab tried to detonate aboard Northwest Airlines flight 253, is among the most powerful of explosives in the world and was widely used to blow up airplanes in the 1970s and 1980s. The only reason the passengers of Flight 253 are still alive today is because Mr. Abdulmutallab’s syringe detonator failed for still unknown reasons. Yet despite the facts that PETN is easily detected and Mr. Abdulmutallab’s father warned the U.S. embassy in Nigeria about his son this November, Homeland Security Secretary Janet …
