The longer Mr. Gates is in office the more the casualty toll in Iraq and Afghanistan seems to weigh on him, aides said. On a visit to an American Army base in Kuwait this month, he walked in shirt sleeves on a sweltering evening through the ”boneyard,” a vast field of hundreds of mangled Humvees, Bradleys and other armored vehicles destroyed in Iraq. It left him in a somber mood, aides who were present said.

Tears welled in his eyes and his voice quavered during a speech last month to a group of marines when he spoke of Maj. Douglas A. Zembiec, who fought in Fallujah in 2004, then volunteered for another tour in Iraq, where he was killed in May. ”Every night I write notes to the families of young Americans like Doug Zembiec,” he said, trying to regain his composure. ”For you and for me, they are not names on a press release, or numbers updated on a Web site. They are our country’s sons and daughters.”

THE OUTSIDER; Defense Chief Keeps Own Counsel on Iraq