The 2003 Invasion of Iraq
Following Saddam Hussein's invasion of Kuwait in 1990, economic sanctions were imposed upon Iraq by the West. These sanctions were not lifted after the 1991 Gulf War, but rather extended. They affected trade and financial instruments; the only resources not subject to sanctions were medicine and some food. Wikipedia calls them "perhaps the toughest, most comprehensive economic sanctions in human history." Approximately a million Iraqi children are estimated to have died as a result of these sanctions.
The sanctions had the goal of weakening Saddam Hussein's grip on power, but they do not appear to have had this effect. After Al-Qaeda attacked the U.S. on September 11, 2001, and the world community overwhelmingly supported a retaliatory invasion of Afghanistan, the administration of President George W. Bush saw the opportunity to mobilize public opinion around another method of unseating Saddam: military force.
In 2002, in response to U.S. demands to reveal any capability for weapons of mass destruction, Iraq let inspectors from the UN into the country. The inspectors found no weapons, but the Bush administration continued to push intelligence agencies for any evidence that would provide justification for war.
On March 20, 2003, a coalition of forces led by the U.S. and Britain entered Iraq in what the U.S. called "Operation Iraqi Freedom," toppling Saddam's government (and his statue, in the invasion's most iconic image) and sending the dictator himself into hiding. By mid-April, the coalition was in control of the country, and President Bush landed atop an aircraft carrier on May 1 to declare, "Mission Accomplished."
Shortly afterward, the insurgency began. The original insurgents were Sunni Muslims, who were a minority in Iraq but had been given special treatment under Saddam's regime, and now feared retaliation from their Shia Muslim neighbors. As the insurgency continued, however, it drew in all manner of anti-American forces, including a new chapter of Al-Qaeda in Iraq.
Even while battling the exponentially growing insurgency, the coalition could claim some successes, including the capture of Saddam Hussein, who was hiding at the bottom of a pit. It also had many setbacks, including the leaked photos of sexually explicit torture being conducted by U.S. forces at Abu Ghraib prison.
By 2006, Iraq was on the brink of civil war, with an average of 960 insurgent attacks per week. General David Petraeus took over the coalition forces, at the helm of a troop surge of more than 20,000 new American troops. Over the next few years, security improved in Iraq, and in August 2010, U.S. troops left Iraqi cities, as part of an eventual timetable that will include all coalition forces being out of the country by the end of 2011. Iraq now has the chance for peace and democracy, but along with the U.S., it has paid a high price.