Pentagon officials and intelligence analysts concede privately that our foes also have a voracious appetite for pornography—hardly shocking behavior for young men, but hard to square with an image of piety. Many laptops seized from the Taliban and al-Qaeda are loaded with smut. U.S. intelligence analysts have devoted considerable time to poring over the terrorists’ favored Web sites, searching for hidden militant messages. “We have terabytes of this stuff,” said one Department of Defense al-Qaeda analyst, speaking on the condition of anonymity. “It isn’t possible that they are encrypting messages in all of this stuff. Some of these guys are just perverts.”

Tawdry though this predilection for porn may be, it is not necessarily trivial. There is, after all, potential propaganda value in this kind of jihadist behavior. Current U.S. public diplomacy centers on selling America to the Muslim world, but we should also work to undermine some of the myths built up around our enemies by highlighting their incompetence, their moral failings, and their embarrassing antics. Beyond changing how the Muslim world perceives terrorists, we can help ourselves make smarter counterterrorism choices by being more realistic about the profile and aptitude of would-be attackers. More and more, as we work to disrupt training efforts, the jihadists we face are likely to be poorly prepared, and while that won’t always ensure a bungled attack, it suggests that terrorists are likely to select targets that are undefended and easy to hit. The United States has spent billions on port security since 9/11, even though terrorists have shown little interest in ports as targets and even less ability to actually strike them. In contrast, even small investments in training for police and airport-security personnel can make a big difference, as these are the people most likely to encounter—and have a chance to disrupt—an unskilled attacker.