No thanks to the US occupation.
WarResisters.org: There are at least two things the people of the United States don't seem to know about the U.S. occupation of Iraq. One is the magnitude of the violence being wreaked on the people of Iraq by the U.S. occupation forces (alone or in conjunction with Iraqi troops). The other is the breadth and extent of Iraqi nonviolent resistance to the violence of the occupation.
Nonviolent demonstrations against the occupation have been occurring constantly since the invasion. Some 20,000 gathered in Firdous Square a few days after the infamous pulling down of Saddam Hussein's statue to demonstrate against the occupiers. And the same has been true in Fallujah, Najaf, Amara, Kut, Basra Mosul, Irbil - all over Iraq. On August 25, the Grand Ayatollah al-Sistani arrived in Najaf at the head of a nonviolent force to put an end to the violence there. He succeeded in brokering a deal between the armed Iraqis and the attacking occupation forces. The nonviolent march to Najaf achieved what more than three weeks of relentless ground and aerial attacks by the occupiers could not.
Sort of like how we never hear about nonviolent Palestinian and Israeli resistance.