In that hesitation to definitively pin the Paris attacks on the Yemeni terror group, some terrorism analysts see a blind spot. The intelligence community primarily viewed AQAP as a collection of bombers. Attacks like Paris seemed both far-fetched—and maybe unstoppable.

One former official, for example, that the Paris attack looked “exactly” like the kind of attack that analysts worried AQAP might inspire or direct others to carry out. But it was also the kind of plot that U.S. security agencies would “have little opportunity to stop,” because it’s much simpler to buy guns than get a bomb onto an airplane. The threat of mass shootings was like a nagging worry, whereas bomb plots were cause for immediate panic.

U.S. officials didn’t have to look far to see what AQAP had in mind. Its English language magazine called Inspire has for years been encouraging readers to launch small-scale attacks, including shootings, against Western targets deemed offensive to Islam. The editors and cartoonists of Charlie Hebdo were on the Inspire hit list.

Two former senior counterterrorism officials described some of the Inspire ideas as “wacky”—such as a ramming cars into crowds. But they also said that the magazine was taken seriously by U.S. analysts. What’s more, they feared that a lone terrorist could be motivated by the magazine to launch a small-scale attack, like a shooting, and that this would be something U.S. security agencies were essentially powerless to stop.