Iraq War Begins

In March 2003, a coalition led by the United States and joined chiefly by the United Kingdom, with smaller contributions from Australia and Poland, invaded Iraq and overthrew the government of Saddam Hussein. The war was justified mainly by the claim that Iraq possessed weapons of mass destruction and might share them with terrorists. No such stockpiles were found, and the conflict that followed reshaped Iraq, the Middle East, and international debates about the use of force.

The background lay in decades of confrontation. Iraq invaded Kuwait in 1990, and a US-led coalition expelled its forces in the 1991 Gulf War. Afterward, the United Nations imposed sanctions and required Iraq to give up its chemical, biological, and nuclear weapons programs, backed by inspections that Baghdad often obstructed. After the September 11 attacks in 2001, the administration of President George W. Bush adopted a more aggressive stance toward governments seen as hostile and potentially dangerous. In late 2002, American and British officials argued that Iraq was rebuilding its arsenal, citing intelligence that later proved flawed or exaggerated. The UN Security Council passed a resolution demanding Iraqi compliance, but it did not clearly authorize an invasion, and countries such as France, Germany, and Russia opposed military action.

The invasion began in the third week of March with air strikes and a rapid ground advance from Kuwait. Iraqi conventional forces collapsed quickly, and Baghdad fell in early April. Saddam Hussein went into hiding and was captured by US troops in December 2003. In May, President Bush declared an end to major combat operations, but the declaration proved premature. The Coalition Provisional Authority, which governed Iraq, dissolved the army and removed many Baathist officials from public life, decisions that critics say left many armed and unemployed men with grievances.

Security deteriorated swiftly. Looting, a growing insurgency, and attacks by groups such as al-Qaeda in Iraq were followed by sectarian violence between Sunni and Shia communities, which peaked around 2006 and 2007. A US troop surge and shifts in local alliances reduced violence for a time. American combat forces withdrew in 2011. Estimates of Iraqi deaths vary widely, from well over a hundred thousand to several times that figure depending on the method, and thousands of coalition personnel also died.

The legacy remains contested. Iraq held elections and adopted a new constitution, but its politics stayed fragile and sectarian. Instability helped create conditions for the rise of the Islamic State, which seized large areas of Iraq and Syria in 2014. Iran's regional influence grew, and public trust in intelligence agencies and Western governments suffered. Inquiries in both the US and Britain, including the UK's Chilcot Report in 2016, concluded that the intelligence had been presented with unwarranted certainty and that postwar planning was inadequate.