The Iraq War, also referred to as the Second Gulf War, was a prolonged conflict in Iraq from 2003 to 2011. It began with the invasion by a United States–led coalition, which resulted in the overthrow of the Ba'athist government of Saddam Hussein. During the US occupation of Iraq, the conflict persisted as an insurgency that arose against coalition forces and the newly established Iraqi government. US forces were officially withdrawn in 2011. In 2014, the US became re-engaged in Iraq, leading a new coalition under Combined Joint Task Force – Operation Inherent Resolve, as the conflict evolved into the ongoing Islamic State insurgency.
The Iraq invasion was part of the Bush administration's broader war on terror, launched in response to the September 11 attacks.