[gleeaikin]

This language map is some help, but a lot of Sunnis, Shiites, Alawis, etc. speak Arabic.

[sefarkas]

The Chinese have about 30 dialects that occasionally share the same the same written character/pictograph, but there is no one spoken language in China, although all of them are referred to as "Chinese". You do not see the Chinese fighting amongst themselves to the same (wildly publicized) degree as the Sunni/Shia folks. Iranian Shia are Persian, not Arab ethnically. The Iran/Iraq war showed ethnicity was more significant than language or religion when it came to choosing sides and declaring loyalty.

Some of the spoken varieties are mutually unintelligible,[4] both written and orally, and the varieties as a whole constitute a sociolinguistic language. This means that on purely linguistic grounds they would likely be considered to constitute more than one language, but are commonly grouped together as a single language for political and/or religious reasons (see below). If considered multiple languages, it is unclear how many languages there would be, as the spoken varieties form a dialect chain with no clear boundaries. See http://en.wikipedia.org/wiki/Arabic_language#Arabic_and_Islam