Arlington, Va. ? Quoting letters of the fallen from the war in Iraq, President Bush vowed Monday to a Memorial Day audience of military families and soldiers in uniform that the nation will honor its dead by striving for peace and democracy, no matter the cost.

“We must honor them by completing the mission for which they gave their lives; by defeating the terrorists,” the president told a supportive crowd of several thousand people at Arlington National Cemetery.

Bush’s remarks come as the U.S. military supports a massive weekend show of force in Baghdad by Iraqi forces aimed at halting insurgent attacks. The violence has killed more than 700 people since Iraq’s new government was announced April 28. The sweep of Baghdad was answered by insurgent counterattacks; south of the city, two suicide bombers blew themselves up Monday in a crowd of police officers, killing up to 30 people and wounding dozens.

The president’s tribute at Arlington came in sharply different circumstances from the Memorial Day visit Bush made to the cemetery’s Tomb of the Unknowns two years ago, just as the nation’s problems stemming from the Iraq war were becoming apparent.

Vietnam veterans and their family members listen to Taps as they pay tribute on Memorial Day at the wall of the Vietnam Veterans Memorial in Washington, D.C.

Before his Memorial Day remarks in 2003, Bush had declared major combat operations at an end, the U.S. government confidently predicted that weapons of mass destruction would be found and American generals said troops were in the process of stabilizing Iraq.

At that time, some 160 American soldiers had been killed in Iraq. Today, the total is more than 1,650.

On Monday, Bush evoked the memories of American soldiers who have died, reading excerpts from the letters they wrote, in some cases letters that were to be opened only in the event that the soldier didn’t make it home.

U.S. Army Sgt. Brian S. Doyne, from Fayetteville, Ga., salutes during the playing of the national anthem at a Memorial Day ceremony at Arlington National Cemetery. Doyne was injured by a roadside bomb in Iraq. President Bush spoke at Monday's ceremony, vowing to continue the fight for freedom in Iraq and Afghanistan.

“My death will mean nothing if you stop now,” Louisiana National Guard Sgt. Michael Evans wrote in a letter home. Evans died Jan. 28 while on patrol in western Baghdad, part of a major security operation to protect the first free Iraqi elections in more than 50 years.

“I know it’ll be hard, but I gave my life so you could live – not just live, but live free,” Evans wrote.

Bush’s nine-minute address was punctuated eight times by applause from a crowd of military families, some of whom were accompanied by soldiers in wheelchairs recovering from their wounds.

As he has done since U.S. forces invaded Iraq in March 2003, the president said the war was part of a greater conflict necessitated by the Sept. 11, 2001, terrorist attacks that claimed nearly 3,000 lives, toppled the World Trade Center and heavily damaged the Pentagon, which is near the cemetery where Bush spoke.

“Two terrorist regimes are gone forever, freedom is on the march and America is more secure,” Bush said of the end of the Taliban regime in Afghanistan and Saddam Hussein’s rule in Iraq.

But it was excerpts from the letters Bush read to the audience that drew tears and the strongest applause.

“Realize that I died doing something that I truly love for a purpose greater than myself,” Marine Capt. Ryan Beaupre of St. Anne, Ill., wrote to his family.