U.S. General: Iraq War Is 'Not Hopeless'

Britain's Prime Minister Tony Blair, left, greets the Allied Forces Commander in Iraq U.S. Lt. General David Petraeus on his arrival at the Prime Minister's residence 10 Downing Street, London, Tuesday Feb. 6, 2007. (AP Photo/Max Nash/pool) (Max Nash - AP)

"But I go away with great pride because we've laid the foundation here," he added. Everything's not as I would have liked or would have wanted it to be."

Casey said he was not ready to discuss mistakes that may have been made during his two and a half years of service in Iraq, but he offered a hint of regret.

"The main point people will debate is whether I relied too much on Iraqi forces rather than American forces," he said, stressing he wasn't agreeing with them, "but that's a point people will debate."

The U.S. Ambassador to Iraq, Zalmay Khalilzad, and the Iraqi National Security Adviser Mowaffak al-Rubaie also attended the ceremony, although Prime Minister Nouri al-Maliki was absent.

Abizaid, who is being replaced as the head of Middle East operations by Navy Adm. William Fallon, thanked Casey for his service and said he was leaving his post in good hands.

"No soldier is more prepared for this mission than Gen. Petraeus," he said.

He also warned the Iraqis that they needed to end the violence between Shiites and Sunnis that has been increasing since the bombing of a Shiite mosque in Samarra nearly a year ago.

"No nation can allow sectarian agendas to define their future," he said. "You are changing the world. Keep your eyes on the promise of a better future."