No, al Qaeda Is Not About to Blow Up Your Blouse

The panic over an alleged al Qaeda plot went into overdrive Monday night, when ABC News reported that terrorists in Yemen were experimenting with a new and virtually undetectable bomb-making technique: dipping their clothes into liquid explosive that then dries and can be ignited.

The cries of doom began almost immediately after the story went online. But people shouldn’t have been so quick to scream. A clothing bomb would almost certainly never work, explosive experts tell Foreign Policy.

From bombs in underwear to the derriere, the explosive-device masters in al Qaeda’s Yemen branch have been sowing fear and panic for several years now. But their dastardly techniques, while technically impressive, have not been shown to consistently have their desired effect: killing lots of people.

It’s not clear from the report that this latest alleged device, which one anonymous official called "ingenious," is directly linked to the recent terror threat that led to the closure of more than 20 U.S. embassies and diplomatic posts. But the use of sophisticated explosives fashioned into hard-to-detect devices fits a pattern of Yemen’s bombmaker craftsmen, and one in particular.

That master bomber, Saudi Arabia-born Ibrahim al-Asiri, is among the world’s most wanted terrorists. The reputed chief bombmaker for al Qaeda in the Arabian Peninsula, which is believed to have been plotting the latest attempted attack, is thought to have designed two of the more clever devices in recent years, which went undetected by security guards and screening systems.

The first was the so-called underwear bomb worn by a young Nigerian man, Umar Farouk Abdulmutallab, aboard a U.S. jetliner bound for Detroit on Christmas Day 2009. The other was a bomb that Asiri is believed to have inserted in his brother’s rectum in an attempted assassination of Saudi Arabia’s counterterrorism chief.

Both bombs have a common thread: Neither of them really worked. Abdulmutallab wasn’t able to ignite his device before fellow passengers saw him fiddling with something in his pants and then subdued him. And the device in Asiri’s brother’s behind did a great job killing him — shearing the suicidal terrorist in half at the waist and blowing one of his arms into the ceiling — but left his target with minor injuries. The man’s body apparently absorbed most of the bomb blast. (A similar attack in Afghanistan last year also left only the bomber dead.)

Despite these qualified failures, Asiri’s legend has only grown in security and counterterrorism circles. His most eye-popping invention is a bomb that was said to be surgically implanted in an attacker’s body. For a host of reasons this seems not only unlikely — the body itself would absorb most of the lethal blast — but physically implausible. (Though this did make a really compelling scene in the 2008 Batman movie The Dark Knight, when the Joker gets a bomb into the Gotham police station by sewing it into a follower’s belly.)

Nevertheless, these attempted attacks have fueled anxiety, not entirely unfounded, that al Qaeda in Yemen is hell-bent on finding new ways to foil security measures meant to detect explosives hidden on, or in, a human body.

Back in 2011, the most-wanted bombmaker developed what John Pistole, the head of the Transportation Security Agency, has called "a next generation device" that was an improvement on his previous bombs. Using a "double initiation system," Asiri’s device used two syringes to mix liquid explosives and was covered in caulk so that it wouldn’t be detected by mechanical screening or bomb-sniffing dogs, Pistole said at the Aspen Security Forum last month.

The explosive itself was also a new type that U.S. security agencies had never seen before, Pistole said. The TSA’s explosive-detection equipment wasn’t calibrated to detect it, and the dogs weren’t trained to smell it. Fortunately, the CIA got the bomb out of Yemen and any attack was disrupted.

Liquids, new explosives, hiding devices in clothing. This sounds a bit like the lethal clothing that ABC is reporting. And it certainly fits with Asiri’s alleged methods.

But given that none of his devices have worked as intended, should Americans be panicking? One explosives expert tells Foreign Policy that while this alleged blouse-bomb may sound terrifying, and remind us of something out of an action flick, it is very risky for the bomber. A device consisting of explosives-dipped clothing, the expert said, is certainly plausible. Cotton is a carbon, and if you add fuel to it, you can create an explosion. But once the attacker starts moving, the clothes will flex, causing heat, shock, friction, and static — all things that make a bomb go boom. "In my opinion, you’ll have a highly unstable bomb that doesn’t have enough power to kill someone within five feet of it," the expert said.

At the Aspen Security Forum, Pistole called Asiri "our greatest threat," and said, "All the intel folks know that is a clear-and-present danger." If that’s true, perhaps we can take some shred of comfort: Unless Asiri, or anyone else, can come up with a device that actually kills more people than just the bomber, these plots are likely to remain aspirational. They may be the stuff of really good movies, but not very effective terror attacks.