While the two sects share the same basic beliefs, differences in hierarchy and doctrine make Catholics and Protestants an apt comparison.
Iraq elected a new president in the latest step toward forming a new government, as a series of attacks killed dozens of people and Islamic militants destroyed a Muslim shrine on Thursday.
Nouri al-Maliki denouced ISIS for forcing Christians in Mosul and other cities to convert, flee the city, or pay punitive taxes.
A new government without a capable military won't mean much. And it doesn't appear that Iraq has one at the moment.
Independence for Iraqi Kurdistan is looking inevitable, with Kurdish fighters seizing more territory from Iraq's central government today. But one key Kurdish faction is wary of going it alone.
Kurdish troops moved on two major oil fields near Kirkuk early Friday, according to the Iraqi Oil Ministry.
In remarks likely to worsen Baghdad's already difficult relationship with the Kurds, Iraqi Prime Minister Nouri al-Maliki said Wednesday the Kurdish self-rule region was harboring Sunni militants.
The discovery of the bodies has reawakened fears of sectarian violence that wracked the country in the mid 2000s.
The video was purportedly filmed on Friday and would be the first public depiction of Abu Bakr al-Baghdadi, the militant group's leader.
The video purports to show Abu Bakr al-Baghdadi, who is the leader of the Sunni insurgent group that has launched powerful insurgencies in Iraq and Syria.
Prime Minister Nouri al-Maliki vowed Friday to fight until the 'Islamic State' militants are defeated. The new Iraqi parliament ended its first session after failing to name his replacement.