The Iraq War was a protracted armed conflict that began in 2003 with the invasion of Iraq by a United States-led coalition that overthrew the government of Saddam Hussein. The conflict continued for much of the next decade as an insurgency emerged to oppose the occupying forces and the post-invasion Iraqi government. An estimated 151,000 to 600,000 or more Iraqis were killed in the first 3–4 years of conflict. The U.S. became re-involved in 2014 at the head of a new coalition; the insurgency and many dimensions of the civil armed conflict continue. The invasion occurred as part of a declared war against international terrorism and its sponsors under the administration of U.S. President George W. Bush following the September 11 terrorist attacks.
The invasion began on 20 March 2003, with the U.S., joined by the United Kingdom and several coalition allies, launching a “shock and awe” bombing campaign. Iraqi forces were quickly overwhelmed as U.S. forces swept through the country. The invasion led to the collapse of the Ba’athist government; Saddam was captured during Operation Red Dawn in December of that same year and executed by a military court three years later. However, the power vacuum following Saddam’s demise and the mismanagement of the occupation led to widespread sectarian violence between Shias and Sunnis, as well as a lengthy insurgency against U.S. and coalition forces. Many violent insurgent groups were supported by Iran and al-Qaeda in Iraq. The United States responded with a troop surge in 2007. The winding down of U.S. involvement in Iraq accelerated under President Barack Obama. The U.S. formally withdrew all combat troops from Iraq by December 2011.
Operation Iraqi Freedom 1… 2… 3…
OIF 2 began at about Mar-Apr 04 when the 1st CAV DIV established TF Baghdad. This lasted until Feb-Mar 05. OIF 3 began at about Feb-Mar 05 when the 3rd ID replaced the 1st CAV DIV. This lasted until Jan-Feb 06 (11 months). With the National Guard and Reserve rotation schedules changing constantly, OIF dates are up for debate.
Statue of Saddam Hussein being toppled in Firdos Square on April 9, 2003 after the US invasion of Iraq. US military website.
Most military service members agree the phases are outlined like this:
OIF I Mar 2003 – Mar 2004
OIF II Mar 2004 – Mar 2005
OIF III Nov 2004 – Nov 2005
OIF IV Mar 2006 – Mar 2007
OIF V Jun 2006 – Jun 2007
OIF VI Jan 2007 – Jan 2008
OIF VII Feb 2008 – Dec 2008
OIF VIII Jan 2009 – Nov 2009
OIF IX Dec 2009 – Sept 2010
September 1, 2010 – Operation Iraqi Freedom is renamed Operation New Dawn to reflect the reduced role US troops will play in securing the country.