A US-led coalition invaded Iraq and removed Saddam Hussein from power in 2003. The invasion unleashed sectarian violence and an insurgency against coalition troops, which included al-Qaeda-affiliated terrorist attacks. The security situation was at best tenuous when the US withdrew from Iraq in December 2011, with near-daily sectarian violence, exacerbated by the rule of former prime minister Nuri al-Maliki, who alienated Iraq’s Sunni community.
The situation deteriorated with the outbreak of civil war in neighbouring Syria and the emergence of the Islamic State, also known as ISIS or ISIL. ISIS emerged from al-Qaeda in Iraq, a central group in the anti-American insurgency that had been neutralised with the assistance of Sunni militia groups known as Sahwa (Awakening). ISIS entered Iraq’s Anbar province in January 2014 and proceeded to expand throughout the year, capturing large swathes of territory in northern Iraq, including the second-largest city Mosul. It set up a ‘Caliphate’, while looting weapons, oil and other resources to fund its continuous expansion. ISIS achieved notoriety when al-Qaeda disavowed it for being too radical, and it has since continued to commit various atrocities against civilians.
A US-led coalition started launching airstrikes against ISIS in August 2014 and has concurrently provided weapons and military assistance to Iraqi troops and allied militias, particularly the Kurdish Peshmerga. Meanwhile, Maliki, who was viewed as part of the political problem, was replaced by the more conciliatory Haider al-Abadi in September 2014. But Abadi, viewed as weak and ineffective, has faced an array of political challenges. He has struggled to rein in the Hashd al-Shaabi (Popular Mobilisation Units), an umbrella of powerful militias that have participated in ground operations against ISIS – some with close ties to Abadi’s opponents and/or Iran. Iraq’s political paralysis is exacerbated by the threat of bankruptcy, as the low price of oil and the high cost of security operations have resulted in a severe economic crisis.