Secretary of Defense Leon Panetta marked the end of the U.S. war in Iraq at a ceremony at the Baghdad International Airport on Thursday.
"We spilled a lot of blood," Panetta said. "But all of that has not been in vain. It's been to achieve a mission making that country sovereign and independent and able to govern and secure itself."
More than 4,500 U.S. troops have been killed and 32,000 wounded in the nearly nine years that have passed since the U.S. invaded Iraq in March 2003. The last soldiers will be out of the country by the end of the year, although the U.S. has pledged to continue to assist the country.
The Defense secretary and a number of other top generals and commanders participated in a ceremony in which the U.S. Forces-Iraq flag was lowered.
“No words, no ceremony can provide full tribute to the sacrifices that have brought this day to pass,” Panetta said.
On Wednesday, President Obama visited Fort Bragg, N.C., to welcome home troops and to congratulate them on this “moment of success.”
Panetta called it a tribute to “everybody who fought in that war, everybody who spilled blood in that war, everybody who was dedicated to making sure we could achieve that mission,” although he acknowledged there would be challenges ahead for Iraq’s nascent democracy.
"They're going to face challenges in the future," Panetta said this week during a trip to Afghanistan. "They'll face challenges from terrorism, they'll face challenges from those that would want to divide their country. They'll face challenges from just the test of democracy, a new democracy and trying to make it work. But the fact is, we have given them the opportunity to be able to succeed."
Some Republicans have argued that the job in Iraq isn’t complete, and that the decision to pull the troops was a political one.
Sen. John McCainJohn McCainMcCain: China has done ‘nothing’ on North Korea Trump administration weighing order to withdraw from NAFTA Graham: There are 'no good choices left' with North Korea MORE (R-Ariz.) blasted the president on the floor of the Senate Wednesday.
"It is clear that this decision of a complete pullout of United States troops from Iraq was dictated by politics, and not our national-security interests," he said. "I believe history will judge this president’s leadership with the scorn and disdain it deserves.”