There was pomp and circumstance in Kabul, Afghanistan, as Gen. David Petraeus handed off the flag of leadership to Marine Corps Gen. John Allen.
Adm. Mike Mullen, chairman of the Joints Chiefs of Staff, praised the work U.S. troops did under Petraeus.
"I can honestly say that although a lot of hard work -- deadly work -- remains before us, I have never seen our progress more real and our prospects more encouraging," Mullen said.
"The enemies of Afghanistan and those who seek nothing more than to strike out against our coalition have been dealt heavy blows over the past year," he said. "They've been pushed out of sanctuary."
The ceremony came just hours after Afghan security forces killed the assassins of Jan Mohammad Khan, a close advisor to Afghan President Hamid Karzai.
The Taliban claimed responsibility for the attack. The bombings and raids have killed 37 international forces this month.
Meanwhile, the U.S. has begun to withdraw a third of its 100,000 troops in Afghanistan.
Over the weekend, 200 Canadian soldiers also packed their bags for the trip home.
As new commander, Allen said he's under no illusions about the task ahead.
"I will continue to support in every way possible, the recruiting, training, preparation and equipping and the fielding and employment of the Afghan national security forces," Allen said.
Gen. Petraeus, the architect of the surge in Iraq, will now retire from the military to become the head of the CIA.