A decade ago, the U.S. and its allies invaded Iraq on the premise that the country was hiding weapons of mass destruction. Despite worldwide protest and a lack of UN authorization, 200,000 thousand troops deployed into Iraq in March of 2003, following massive airstrikes. The coalition faced minimal opposition, and Baghdad quickly fell. For years after President George W. Bush's "mission accomplished" speech, the war raged on, fueled by sectarian conflicts, al Qaeda insurgencies, outside agencies, and mismanagement of the occupation. Ten years later, we look back in a three-part series. Today's entry focuses on the March 20, 2003, invasion of Iraq, and the weeks immediately following. This entry is part 1 of 3, be sure to see part 2, and part 3.