The United States led an international coalition in a military invasion of Iraq on 20 March 2003.
Following the September 11 terrorist attacks on the World Trade Center in New York and the Pentagon in 2001, the American administration framed the invasion as a pre-emptive strike within the broader Global War on Terror, alleging unproven ties between Iraqi President Saddam Hussein and terrorist groups like al-Qaeda.
The primary justification given by US President George W. Bush and UK Prime Minister Tony Blair was that Iraq possessed or was developing Weapons of Mass Destruction (WMDs). After the invasion, these intelligence claims proved to be false, and no WMDs were ever found.
The United Nations (UN) Security Council refused to pass a resolution explicitly authorising the use of military force, so America and the UK bypassed the UN, moving forward with a “coalition of the willing”.

The war – officially named “Operation Iraqi Freedom” by the US and “Operation Telic” by the UK – opened with a massive “shock and awe” aerial bombardment campaign in Baghdad designed to rapidly destroy Iraqi command and control networks.
Coalition ground forces – primarily from the United States and Britain, with smaller contingents from Australia and Poland – invaded from Kuwait, swiftly bypassing major forces to march directly to the capital.
US forces entered the centre of Baghdad on 9 April 2003. The toppling of a large statue of Saddam Hussein in Firdos Square became the iconic visual symbol of the regime’s collapse.
On 1 May 2003, President Bush famously declared an end to major combat operations in front of a “Mission Accomplished” banner aboard an American aircraft carrier.
Saddam Hussein fled into hiding but was captured by US forces in December 2003. He was tried by an Iraqi tribunal and executed by hanging in 2006.

The sudden dismantling of the Iraqi military and ruling Ba’athist state apparatus by the Coalition occupiers created an immense power vacuum, which sparked widespread looting, a violent anti-coalition insurgency, and a brutal sectarian civil war between Shia and Sunni factions.
By the time the US formally completed its military withdrawal in December 2011, the conflict had cost approximately $3 trillion and resulted in the deaths of roughly 4,500 US service members and well over 100,000 Iraqi civilians.
The instability from the war permanently shifted the balance of power in the Middle East. It also severely strained Western diplomatic alliances and created breeding grounds for regional extremist groups, including the rise of the Islamic State (IS).

The war also profoundly transformed the domestic politics of the United States and the United Kingdom, shattering public trust in government intelligence and leading to widespread public cynicism toward official government justifications for war.
Rising public discontent in America directly fueled the Democratic Party’s takeover of Congress in the 2006 midterms and propelled Barack Obama – who had famously opposed the war from the beginning – to the presidency in 2008.
British Prime Minister Tony Blair faced fierce resistance from within his own Labour Party and the British public, particularly over the “Downing Street memo” and allegations that intelligence was manufactured to justify the invasion.

A massive public inquiry led by Sir John Chilcot concluded that the UK chose to join the invasion before peaceful options were exhausted, and that the intelligence presented to Parliament was flawed, severely damaging the political legacy of Blair’s government.
Finally, the removal of Saddam Hussein – Iran’s fiercest regional rival – unintentionally eliminated the primary counterweight to Iranian power, allowing Iran to drastically expand its political and military influence over a newly Shia-led Iraq.









