As I said yesterday
, I have no way of knowing whether the alleged letter from Zawahirir is real or not. Juan Cole does though.
The very first element of the letter is the blessing on the Prophet. It says:
al-salah wa al-salam `ala rasuli'llahi wa a-lihi wa suhubihi . . .
(peace and blessings be upon the Messenger of God and his family and his companions . . .)
the phrase "salla Allahu `alayhi wa alihi wa sallam" (the blessings and peace of God be upon him and his family) is a Shiite form of the salutation, because of the emphasis of the Shiites on the House or descendants of the Prophet. Because of the cultural influence of Shiism in South Asia, one does find that form of the salutation in Pakistan and India among Sunni Muslims.
But before I went to Pakistan I had never, ever heard a Sunni Muslim add "wa alihi" (and his family) to the salutation. I associated it strongly with Iran and Shiism, and was taken aback to hear Sunnis say it on Pakistani television. Certainly, I never heard that form of it all the time I lived in Egypt.
Again, I'm can't judge the validity of this argument either (and my post yesterday was really decrying the use of the military in propaganda). I recommend you read the whole thing, though.