While the Obama administration has dramatically reduced the number of troops and rebranded the mission, the operation in Hawija was a reminder that U.S. forces are still engaged in hunting down and killing al-Qaida militants — and could still have to defend themselves against attacks.

That reality was front and center at a change-of-command ceremony in one of Saddam Hussein's former palaces outside Baghdad that the American military now uses as its headquarters. Officials warned of a tough road ahead as the U.S. moves into the final phase of the 7 1/2-year war.

Of paramount concern is Iraqi leaders' continued bickering, six months after parliamentary elections, over forming a new government — a political impasse that could further endanger stability and fuel a diminished but still dangerous insurgency.

"Iraq still faces a hostile enemy who is determined to hinder progress," Gen. Lloyd Austin, the newly installed commander of the just under 50,000 U.S. troops still in Iraq, told the swelling crowd that was clad in military fatigues and political suits. "Make no mistake, our military forces here and those of the Iraqi nation remain committed to ensuring that our friends in Iraq succeed."

AP