The religion's two major sects are Sunni and Shia. In Iraq, Sunni Arabs comprise 15% to 20% of Iraq's population, with about half in urban areas like Baghdad, Mosul and Tikrit, according to the Council on Foreign Relations. About 18% of Iraq's population is Sunni Kurds.
That means the vast majority of Iraqis are Shiite Muslims.
During his decades-long rule, Saddam Hussein gave positions of power to Sunnis, and marginalized Shiites, according experts. Shiite families fled to Iran and the country gave them housing and jobs and educated their children. “That imbued Iraqi Shiites who have returned home with a fierce allegiance to Iran,” they said.
What are terrorism experts saying?
Jessica Stern, a lecturer on terrorism at Harvard University wrote this, "ISIS: The State of Terror," says it's imperative to address the sectarian divisions in Iraq and continue pushing for changes in its government, in the CNN report.
She notes that "the anti-Sunni, Shia-promoting government of Maliki" was a big reason ISIS was able "to take root" in Iraq.
"Many Sunnis feel under siege. ISIS is saying, 'We're going to protect you. ISIS is presenting itself as a savior of Sunnis," she said.
U.S. Army Lt. Col. Rick Francona, a CNN military analyst.
"The Iranians are smart enough to know that's a possibility, so they would be telling the Shia-led militias not to make this a Sunni v. Shia fight," Francona said.
Should the US consider Iran's efforts to defeat ISIS by backing Shia-led militias?
Speaking at the congressional hearing about the White House's request for use of force to fight ISIS, the chairman of the US Joint Chiefs of Staff reminded the gathering that Iran's involvement in helping Iraqi forces is a good thing.
"Anything anyone does to counter ISIS is in the main a good outcome," Gen. Martin Dempsey said.
Defense Secretary Ashton Carter suggested that the matter was more nuanced. The US is worried about Iran's role, he said.
"It is something that is concerning to us," he said of Iran's role, "in particular because the sectarian danger in Iraq is the principal thing that can unravel the campaign against ISIS."
For now fighting back ISIS appears to be the main focus and is experiencing success, but sectarian divisions in the region definitely will be a challenge moving forward once ISIS has ultimately been degraded. The ability to create long standing peace will be decided by the ability of the Shia and Sunni to present a united front against further incursions by ISIS.
Still, trust is one of the main considerations, and some believe it is thin when dealing with Iran. Senator Bob Corker (R-Tenn.), the committee chairman, wondered aloud if the Iranian-backed militia might attack the 3,000 American troops currently in Iraq.
“We have no indications that they intend to turn on us,” Dempsey said.
is retired and lives in Clearlake, California. She has three grown
children and one grandson and a Bachelor’s degree in Health Services
Administration from St. Mary’s College in Moraga California. On the
home front Dava enjoys time with her family, reading, gardening, cooking