ISIS recruits thousands of Westerners to their jihad, many of whom might come home to continue the war. Al-Qaeda has attempted a number of attacks on the US and its facilities over the last several years, with one attack — Fort Hood, inspired by AQAP — resulting in the death of 14 people. A few days ago, al-Shabaab threatened to attack the Mall of America as one of its global targets. Homeland Security Secretary Jeh Johnson advised us to “be careful” and to speak up when suspicious activity occurs, but assured us that US counterterrorism experts were on the job. They’re focused and vigilant, and if the perps turn out to be underage girls, they’ll be all over them.

No, really, James Rosen (no relation) reported exclusively last night to Fox News:

A senior State Department official in charge of federal counterterrorism programs was arrested Tuesday afternoon for allegedly soliciting sex from a minor, Fox News has learned.

Fairfax County Police officials say Daniel Rosen was arrested by a county detective about noon at his Washington, D.C. home after he allegedly sought to arrange sex with a minor. The detective, a female officer working in the county’s Child Exploitation Unit, had been posing as the minor in online exchanges with Rosen, police said.

Rosen, who is the director of counterterrorism programs and policy at the State Department, was arrested and transported to the D.C. jail and charged with one count of Use of a Communications Device to Solicit a Juvenile. …

A source with Diplomatic Security, the law enforcement agency housed within the Department of State, told Fox News that law enforcement officers were “hitting [Rosen’s] phones,” meaning that a search warrant had been issued so police could examine the devices for additional evidence.

State assures us that his security clearance has been suspended … now:

In a statement issued Tuesday night, State Department spokeswoman Jen Psaki said the department was aware that one of its employees had been arrested and charged but “for issues related to Department personnel and for privacy reasons” could not identify the person or the charges.

“His security clearance will be suspended and he will be put on administrative leave while this proceeds to its end through any judicial process,” Psaki said.

That’s terrific. Here’s a question: how did Rosen keep it in the first place? Sexual predators don’t usually manifest themselves in their mid-40s, for one thing. Yet Fairfax County law enforcement had little difficulty in catching up to Rosen, while the entire counterterrorism apparatus at State apparently had no idea that their leader was allegedly trolling underage girls on the Internet. Have they ceased doing routine reviews of high-access clearances at State? If so, where else has this practice gone by the wayside?

And here’s another question: who else may have known about Rosen’s alleged activities? If another government did a better job at vetting our counterterrorist program leaders than we did, then they might have had powerful leverage over Rosen. That’s precisely the kind of risk that clearance investigators are supposed to find ahead of time. There’s no indication yet that this went any farther than where it is now, but the potential for penetration into our counterterrorism operations would have been enormous had it been discovered by agents of less-than-friendly countries willing to either satiate the appetite or blackmail on the basis of it.

Perhaps this will turn out to be a misunderstanding, and Rosen will be cleared of the charges. If it’s on the level, this is a jaw-dropping wake-up call to Congress to start demanding a lot more answers about security procedures in some of our most sensitive national-security efforts. The Senate Foreign Relations Committee should haul John Kerry to Capitol Hill to provide those answers ASAP.