Iraq Civil War

The Shia are the majority population in Iraq.
The Sunni are in the majority in the Islamic umma.

This allowed the Sunni to designate the Shia as heretics of Islam.

The result is that this is the dominant primary endless unresolved war between these two sects of Islam.

A subset of this war is now unfolding. It is between the new insurgency of Sunni Isis and the Shia in Iraq:

http://www.aljazeera.com/news/middleeast/2014/06/iraq-rebels-battle-baquba-city-2014617124856327794.html

All other non-Sunni Islamic sects will support the Shia.

The significant neutral will be Wahabi Saudi Arabia because the Saudi Royals are too corrupted in the ways of Satan to want to side with the religiously virtuously pure Shia. If they were religiously virtuously pure then they would side with the Shia and end all their connections with the U.S.

In fact at the core of Saudi Arabia this is what their national populace would desire above all.