Washington ? On the desk of Gen. Peter Pace is a photograph of the first Marine who died following Pace’s orders: Lance Cpl. Guido Farinaro, killed in combat in Vietnam in 1968 when the general was a lieutenant.

That photo is a sign of his devotion to the troops, President Bush said Friday, naming Pace to serve as the nation’s top military officer, the chairman of the Joint Chiefs of Staff.

Since becoming vice chairman on Oct. 1, 2001, Pace has quietly helped shape the Pentagon’s role in the global war on terrorism. If he is approved by the Senate, he will take command of a military fighting guerrilla wars in Iraq and Afghanistan even as it reshapes itself toward Defense Secretary Donald H. Rumsfeld’s vision of a lighter, more flexible force.

The selection of Pace signals no stark change in direction from the command of his boss, Air Force Gen. Richard Myers, due to retire Sept. 30 after four years on the job. In the past, vice chairmen have focused on weapons acquisition, but Pace has said 80 percent of his duties are devoted to operations in the war on terrorism.

In a ceremony at the White House, Pace thanked Bush for his “trust and faith in me.” He said the promotion was “exhilarating,” but added, “I know the challenges ahead are formidable.”

Pace, 59, is expected to win Senate confirmation easily. He is the first Marine to be named chairman.

The combat operations Pace has played a direct role in — Vietnam, Somalia, and the current wars in Afghanistan and Iraq — are not regarded as as America’s clearest victories.

In Vietnam, as an officer fresh out of the Naval Academy in 1968, he commanded a rifle platoon and saw action in Hue City.