Arthur Silber:

A few weeks ago, I took the F.B.I.’s temperature again. At the end of a long interview, I asked Willie Hulon, chief of the bureau’s new national security branch, whether he thought that it was important for a man in his position to know the difference between Sunnis and Shiites. "Yes, sure, it’s right to know the difference," he said. "It’s important to know who your targets are."

That was a big advance over 2005. So next I asked him if he could tell me the difference. He was flummoxed. "The basics goes back to their beliefs and who they were following," he said. "And the conflicts between the Sunnis and the Shia and the difference between who they were following."

O.K., I asked, trying to help, what about today? Which one is Iran — Sunni or Shiite? He thought for a second. "Iran and Hezbollah," I prompted. "Which are they?"

He took a stab: "Sunni."

Wrong....read on