Defense Secretary Leon E. Panetta, the most senior U.S. official at the ceremony, told those who attended that America’s role in Iraq is by no means over. He referred to a $6 billion effort being undertaken by the State Department to sustain U.S. influence now that the military role has ended.

“Challenges remain, but the U.S. will stand by the Iraqi people as they navigate those challenges to build a stronger and more prosperous nation,” he told the gathering.

A newly established Office of Security Cooperation-Iraq (OSCI), under the auspices of the U.S. Embassy, will retain 157 military personnel to continue to help train the Iraqi security forces. The State Department will also employ thousands of private security contractors to assume many of the functions that had been performed by the military and cannot be dispensed with given the dangerous conditions.

The air terminal where the ceremony was held is a former military facility that henceforth will be operated by the embassy. The State Department will also run a fleet of 80 MRAP (mine-resistant, ambush-protected) armored fighting vehicles to transport diplomats, using civilians who have been taught by the military to drive them.