President Bush (search) led the nation on Monday in remembering all Americans who have died in war, including soldiers killed in Afghanistan and Iraq, some now resting in fresh graves at Arlington National Cemetery just beyond the Tomb of the Unknowns.

"The moral force of democracy is mightier than the will and cunning of any tyrant," Bush said under overcast skies at the cemetery.

"Today, we recall that liberty is always the achievement of courage and today we remember all who have died, all who are still missing and all who mourn."

Bush's remarks came on one of the most violent days for American troops since the war in Iraq ended last mnonths. One soldier was killed and another wounded when gunmen ambushed an Army convoy in northern Iraq. In Baghdad, a soldier was killed and three were injured when their Humvee ran over a land mine in an apparent attack, U.S. Central Command (search) said.

Defense Secretary Donald H. Rumsfeld said continuing threats to America's freedom "will be met with the same courage and the same commitment and like the foes of times past, they too will be defeated."

Joining the president at an outdoor amphitheater near the Tomb of the Unknowns (search) was Gen. Richard Myers, chairman of the Joint Chiefs of Staff, who said on a TV talk show appearance that he was "confident" weapons of mass destruction will be found in Iraq.

It will take time to find such weapons, Myers said in a television interview, but the general noted that the United States is now gathering information from its interrogations of a number of prisoners. The assertion that Saddam Hussein had weapons of mass destruction was the Bush administration's stated reason for going to war.

Cannons sounded as the president's motorcade moved along winding roads of the cemetery where troops stood at attention, rifles with shiny bayonets on their shoulders. Tiny American flags had been stabbed in the damp grass in front of many the cemetery's white headstones that stand in rows like marching soldiers.

"This nation does not forget," Bush declared after placing a wreath on the tomb and standing stoically with his hand on his heart as "Taps" was played. He said the nation honors those in uniform from "conflicts in Korea and Vietnam to the trials of world war, to the struggles that made us a nation."

Most of the service was somber, but the crowd chuckled when Bush recalled a letter that Army Staff Sgt. Lincoln Hollinsaid, 27, of Malden, Ill., wrote from the Middle East, telling his family that he enjoyed getting mail from them. "I wish my truck and boat knew how to write," Bush said, quoting Hollinsaid, who was killed April 7. "I sure do miss 'em."

The president also quoted from a letter that Army Capt. James Adamouski, 29, of Springfield, Va., wrote to his wife, shortly before he died in a helicopter crash on April 2. "I do my job 110 percent and don't get distracted or discouraged when I'm out flying on missions," Bush said he wrote. "However, when I have some down time and get to really thinking, I realize that for all the good things we're doing here, I just plain miss you."'

Before attending the ceremony at Arlington, Bush hosted a reception for about 200 members of veterans service groups, the families of prisoners of war and those missing in action and relatives of troops killed in battle. Included at the event was the family of Army Pfc. Lori Piestewa, the only servicewoman killed in the Iraq war.