Anwar al-Awlaki used to be the imam at a mosque in northern Virginia frequented by Hasan. Awlaki now lives in Yemen -- where Umar Farouk Abdulmutallab reportedly claimed the Detroit explosive device was acquired.
"From what I've heard, the relationship would have been closer than what Awlaki had with Hasan," said Rep. Peter Hoekstra of Michigan, the top Republican on the House Permanent Select Committee on Intelligence.
In the wake of the Detroit plot, debate has renewed among civilian authorities about how to screen for terrorists without appearing to discriminate against Muslims.
The U.S. military, though, has been grappling with this for a while.
It would seem a delicate matter at first blush: How does the Pentagon determine if there are other murderous traitors in its ranks without appearing anti-Muslim?
The answer is twofold.
First, it's not as delicate as it might appear. You review all military branches for any signs of extremism or anti-American leanings of any kind, without regard to race, creed or any other characteristic of the subject.
Second, you don't worry about being delicate.
The latter point should be obvious enough. This is not the Peace Corps or the Sisters of Mercy we're talking about. This is the U.S. Armed Forces, which is still the best fighting force in history -- but cannot remain so if its mission is tethered to a blind and faint-of-heart political correctness.
The Pentagon's up-and-down review of its ranks -- announced in the aftermath of the Fort Hood bloodbath -- must be as bold and brave and blunt as our fighting men and women are trained to be.
That means confronting harsh realities -- one of them being, in this case, that the Army may have made its soldiers vulnerable to an Islamic radical in part because it was too timid to confront religious radicalism in its midst.
It's clear now that the Army saw a number of red flags in Hasan's case well before he slaughtered his comrades in the name of Allah. Evidence suggests that his religious extremism and anti-Americanism was in plain view and wasn't dealt with -- and, in fact, may have been accommodated precisely because he was a Muslim. One official was said to have been concerned about how it might look to confront a Muslim in the ranks.
While the Pentagon cannot worry about being delicate at this point, it can be professional. The probe need not be a witch hunt for Muslims. Again, it need only seek out evidence of any kind of extremism or anti-Americanism in the ranks.
Still, this is no time to be delicate. You don't necessarily look for Islamic radicalism. But you don't look away from it, either.