Take Representative Terry Everett, a seven-term Alabama Republican who is vice chairman of the House intelligence subcommittee on technical and tactical intelligence.

“Do you know the difference between a Sunni and a Shiite?” I asked him a few weeks ago.

Mr. Everett responded with a low chuckle.  He thought for a moment: “One’s in one location, another’s in another location.  No, to be honest with you, I don’t know.  I thought it was differences in their religion, different families or something.”

To his credit, he asked me to explain the differences.  I told him briefly about the schism that developed after the death of the Prophet Muhammad, and how Iraq and Iran are majority Shiite nations while the rest of the Muslim world is mostly Sunni.  “Now that you’ve explained it to me,” he replied, “what occurs to me is that it makes what we’re doing over there extremely difficult, not only in Iraq but that whole area.”

It goes on like that through interviews with the above House intelligence subcommittee vice-chair, as well as the chairwoman of another House intelligence subcommittee, a former FBI counterterrorism chief, and the current FBI national security chief.