Gen Pace is a low-key officer
Gen Peter Pace is the first Marine Corps officer to serve as chairman of the US military's Joint Chiefs of Staff.
Reportedly known in Pentagon circles as "Perfect Pete", he was a rifle platoon leader in Vietnam and served in Korea and in Somalia.
Gen Pace, 59, is seen as closely aligned with former Defense Secretary Donald Rumsfeld, and a man who has helped shape the Pentagon's role in the global war on terror.
He has been vice chairman of the Joint Chiefs of Staff since 2001 and previously headed Southern Command, responsible for US military operations in Latin America.
Gen Pace is a low key officer who does not have much of a public profile.
He was born in Brooklyn, New York, and raised in Teaneck, New Jersey.
A graduate of the US Naval Academy, he received his commission in 1967.
The next year, he was sent to Vietnam, serving as a rifle platoon leader and later as an assistant operations officer.
He served in Somalia as deputy commander of Marine forces.
Gen Pace is married and has a son and a daughter.
'Smart and exceptionally capable'
President George W Bush said of him: "The first thing America needs to know about Pete Pace is that he is a Marine.
"To the American people, the Marine is shorthand for can-do, and I'm counting on Pete Pace to bring the Marine spirit to these new responsibilities."
The United States considers itself at war on a global scale against terrorists.
It is fighting an insurgency in Iraq which has caused 1,300 US casualties. Operations there and in Afghanistan have severely stretched America's army and recruiting is getting harder.
Meanwhile, US military spending is running at around half a trillion dollars a year at a time of big budget deficits.
"He's got a strong background, and he's smart and exceptionally capable," Anthony C Zinni, a retired general in the Marines, told the New York Times.
But he added that Gen Pace was "going to have to decide when he's going to stand up" to the Pentagon's civilian leaders.
The chairman of the Joint Chiefs is the president's main military advisor, but he does not have direct command over forces.