The Iraqi civil war was a civil war fought mainly between the Iraqi government along with American-led coalition forces and various sectarian armed groups, mainly Islamic State of Iraq and the Mahdi Army, from 2006 to 2008. In February 2006, the anti-American insurgency escalated into a sectarian civil war after the bombing of Al-Askari shrine, considered as a holy site in Twelver Shi'ism. US President George W. Bush and Iraqi officials accused Al-Qaeda in Iraq of orchestrating the bombing, although AQI publicly rejected any links to the attacks. The incident set off a wave of reprisals by Shia militants on Sunni civilians, followed by Sunni counterattacks on Shia civilians.
The UN Secretary General stated in September 2006 that if patterns of discord and violence continued to prevail, the Iraqi state was in danger of breaking up. In a 10 January 2007 address, President George W. Bush stated that "80% of Iraq's sectarian violence occurs within of the capital. This violence is splitting Baghdad into sectarian enclaves, and shakes the confidence of all Iraqis.". The conflict escalated over the next several months until by late 2007, the National Intelligence Estimate described the conflict as having elements of a civil war. In 2008, during the Sunni Awakening and the U.S. troop surge, violence declined dramatically. However, an insurgency by ISI continued to plague Iraq following the U.S. withdrawal from the country in late 2011. In June 2014 the Islamic State of Iraq and the Levant, the successor of Islamic State of Iraq, launched a major military offensive in Iraq and declared a self-proclaimed worldwide Islamic caliphate, leading to another full-scale war in Iraq from 2013 to 2017 in which Iraq declared full victory against the terrorist group.
In October 2006, the Office of the United Nations High Commissioner for Refugees (UNHCR) and the Iraqi government estimated that more than 370,000 Iraqis had been displaced since the 2006 bombing of the al-Askari Mosque, bringing the total number of Iraqi refugees to more than 1.6 million. By 2008, the UNHCR raised the estimate of refugees to a total of about 4.7 million (~16% of the population). The number of refugees estimated abroad was 2 million (a number close to CIA projections) and the number of internally displaced people was 2.7 million. The Red Cross stated in 2008 that Iraq's humanitarian situation was among the most critical in the world, with millions of Iraqis forced to rely on insufficient and poor-quality water sources.
According to the Failed States Index, produced by Foreign Policy magazine and the Fund for Peace, Iraq was one of the world's top 5 unstable states from 2005 to 2008.
Participants
A multitude of groups formed the Iraqi insurgency, which arose in a piecemeal fashion as a reaction to local events, notably the realisation of the U.S. military's inability to control Iraq. Beginning in 2005 the insurgent forces coalesced around several main factions, including the Islamic Army in Iraq and Ansar al-Sunna. Religious justification was used to support the political actions of these groups, as well as a marked adherence to Salafism, branding those against the jihad as non-believers. This approach played a role in the rise of sectarian violence. The U.S. military also believed that between 5 and 10% of insurgent forces were non-Iraqi Arabs.
AQI and groups associated with it steadily became a brutal and wasteful foreign occupation force, engaging Yemeni, Saudi, Moroccan, Palestinian, Syrian and Lebanese foreign fighters. Independent Shi'a militias identified themselves around sectarian ideology and possessed various levels of influence and power. Some militias were founded in exile and returned to Iraq only after the toppling of Saddam Hussein, such as the Badr Organization. Others were created since the state collapse, the largest and most uniform of which was the Mahdi Army established by Muqtada al-Sadr and believed to have around 50,000 fighters.
Conflict and tactics
Non-military targets
Attacks on non-military and civilian targets began in earnest in August 2003 as an attempt to sow chaos and sectarian discord. Iraqi casualties increased over the next several years.
By the end of 2008, where the civil war had ended, there was evidence of a decrease in civilian casualties, and likewise in ethno-sectarian casualties. The commanding general of the Multi-National Force-Iraq (MNF-I), Raymond Odierno, testified before the House Armed Services Committee in September 2009 that overall attacks had decreased 85% in the last two years from 4064 in August 2007 to 594 in August. 2009: with 563 attacks in September (through September 28).