Flanked on all sides by anti-aircraft missiles and troops in battle dress, U.S. officials commemorating the one-year anniversary of Sept. 11 attacks at the Pentagon pledged that its victims would be avenged in a continued war against terrorism.

"We renew our commitment to win the war that began here," said President Bush, who led Wednesday's ceremony from a podium just outside the completely rebuilt sandstone wall that a year ago had been a blazing hole of twisted metal and death.

It is here where American Airlines Flight 77, commandeered by hijackers on a homicide mission, cut a five-story gash into the western side of the massive structure, the heart of Naval Command Center, killing 125 people on the ground and all 59 people aboard.

"Those who died in tragedy, they did not die in vain," he said. "Their loss has moved a nation to action."

The day's ceremonies began with a moment of silence at 9:37 a.m. Eastern Daylight Time, the precise moment the plane hit the building, and within an hour after two jet liners crashed into the two World Trade Center towers in New York, killing almost 3,000 people.

Gen. Richard Myers, chairman of the Joint Chiefs of Staff, pledged the full force of the U.S. military to right the wrongs of Sept. 11 and to protect "freedom loving people around the world" from future terrorist attacks.

"I think we are a nation that refuses to dwell on past sorrows," he said. "We will be victorious."

Secretary of Defense Donald H. Rumsfeld recognized that despite the terrorists' intentions, Americans have emerged from the tragedy with pride, patriotism and the conviction to rebuild, just as the massive structure behind him was put back together brick by brick, and even improved.

"Charity and courage, patience and perseverance," he said, in describing the American spirit today. "You have helped, you have prayed, volunteered, given your sons and daughters to the war effort."

His audience swelled with families, members of the military community, 70 congressmen who had been ferried to the Pentagon by Air Force buses and Washington officials of varying rank. They were also joined by several international leaders who had pledged their country's help in the war on terror.

"[It's] the greatest military coalition ever assembled in human history," Rumsfeld said. "We say to you, thank you for standing with us."

From the first strains of the American anthem, to the final flyover of four F-16s, tearful faces dotted the crowd, as photos of loved ones were raised in the air, and soldiers in crisp uniforms stared ahead determinedly to the podium. The president looked on as about 100 schoolchildren whose classmates were aboard Flight 77 recited the Pledge of Allegiance.  Navy and Army bands played music and prayers were made rededicating lives to the American dream.

Bush said he realized that "memories of a great tragedy remain here," but the Pentagon is "a working building, not a memorial," emphasizing that the war effort is strong and backed by the proud people who work there.

"I came to this presidency with respect for all who wear the American uniform," he said. "Everyday as commander-in-chief, my respect has deepened. I am proud of all those who have fought on my orders and this nation honors all who have died in our cause."

As of this month, 50 American servicemen and women have died in the line of duty overseas. "America is counting on you," said Bush. "Our confidence is well-placed."

Of the military personnel who died at the Pentagon on Sept. 11, 64 received individual burials at Arlington National Cemetery. Two memorial headstones were laid and one group burial occurred.  Of the total dead, five families did not receive any remains of their loved ones, including those of a three-year-old girl who perished with her entire immediate family on the plane.

In addition to the deaths, about 100 people were seriously injured on the ground, and many of them are still struggling to recover from serious burns and other injuries.  Many were at the Pentagon today.

Unlike the gaping hole that is now Ground Zero in lower Manhattan where the towers once stood, the damage wrought by the terrorist attack here is but a memory. Ever since that tragic day, work has continued at the Pentagon practically around the clock to rebuild the structure, which is the heart of the U.S. defense community.

Under the auspices of the "Phoenix Project," the damaged section was rebuilt thanks to nearly 3,000 construction workers determined to get the work done before the one-year anniversary of the attack.

And they did it, ahead of schedule and underbudget. The first office workers began moving back into this part of the building one month ago, the last just a few days ago.  The cost was expected to reach $740 million.  It totaled just over $500 million.

Construction workers on the Phoenix Project were paid tribute in a separate ceremony at the Pentagon Wednesday afternoon. Deputy Secretary of Defense Paul Wolfowitz likened the construction workers to soldiers, taking on the battle cry of American resolve and resilience before the flames had even been extinguished on Sept. 12.

"The days and months that followed, you worked and sacrificed, night and day, weekends and holidays, rain or shine. Your families supported you in this labor for America, for that is what it was" he said.

"You have repaired this wall and have in effect, healed the nation," he added.

Wolfowitz accepted an award from the National Trust for Historic Preservation and the Advisory Council for Historic Preservation Trust, and commended the efforts Lee Evey, the program manager for Project Phoenix.

Evey's voice broke as he described the crews who had worked so tirelessly to bring the Pentagon to the point it is today.

"America, we give you back your Pentagon," he said to cheers from the thousands in attendance.

But that is the only thing that seems to remain the same at the military complex. Today, armed military Humvees are stationed outside the perimeters of the Pentagon daily for passing motorists to see. On Wednesday, helmeted troops with assault rifles ringed the entrances amid tight security that has become commonplace here. Missiles were ordered in place around the Pentagon, as well as the rest of Washington, on Tuesday.

At booths around the massive building this week, social workers offered assistance to those experiencing depression and anxiety as the one-year anniversary loomed. Meanwhile, the rest of the Metro D.C. area remains on high alert, as does the rest of the nation.

Rumsfeld said that the nation has already moved on to the next phase, and that is to aggressively defend itself from future attacks.

"Let us do more than remember, the best memorial we can fashion for [the victims] is to protect our security for the generations to come," he said. "That is our charge, that is our responsibility."