The Iraq War, or the War in Iraq (also referred to as the Occupation of Iraq, the Second Gulf War, or Operation Iraqi Freedom by the United States military), was a conflict that occurred in Iraq from March 20, 2003 to December 18, 2011, though sectarian violence continues since and caused hundreds of fatalities.  Prior to the war, the governments of the United States and the United Kingdom claimed that Iraq's alleged possession of weapons of mass destruction (WMD) posed a threat to their security and that of their coalition/regional allies.