What's the difference between a Shiite and a Sunni?

It sounds like a bad joke, but the punch line isn't so funny. Jeff Stein reports in The New York Times that many U.S. counterterrorism officials don't know the answer (free account needed):

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.”

Mr. Everett got the last sentence right. To be honest I didn't know much about the difference, but I knew more than some people interviewed; plus I'm not creating our nation's antiterrorism policy. If you're interested, here are the wikipedia entries for Sunni and Shiite.

Update: Here is a link to the NYT article that does not require an account.