"Early on, it was very difficult, especially being half a world away from where things were happening," Blackwell, 40, said from Bagram Air Base. "So this is my opportunity."

About five months into a yearlong deployment, about 5,500 Schofield Barracks soldiers will be remembering 9/11 today in Afghanistan, the focal point for Operation Enduring Freedom.

At Bagram, the theme of "Values Rebuilding America" will be emphasized at a commemoration with command remarks on honor, courage, freedom, sacrifice and faith.

At Kandahar Airfield, the troops will watch a slide presentation titled "Moments of Silence" about the terrorist attacks on Sept. 11, 2001, at the World Trade Center, at the Pentagon and over Pennsylvania that killed nearly 3,000.

For some Schofield soldiers, the passage of three years has brought new reflection on the attacks, and a unique perspective on serving in the country where the United States continues the still-complicated mission of suppressing the al-Qaida and Taliban forces that spawned them.

Lt. Col. Larry Adams-Thompson, a chaplain who was at the Pentagon on 9/11, found that the attack unexpectedly dredged up old ghosts from his days as an infantryman with the 25th Division in Vietnam in 1969 and 1970.

For Maj. Andy Preston, who also was at the Pentagon, being in Afghanistan is not about getting even.

"For me and the people I work with, this is not some sort of revenge mission," he said, "because it's not the people of Afghanistan (we oppose). We're here to help them and make sure September 11s don't happen again."

Lt. Col. Clarence Neason, meanwhile, said the threat of al-Qaida and terrorism hasn't diminished with the passage of three years. Neason was across the Potomac River when the plane hit, but rushed back to the Pentagon to help evacuate the injured.

"No, I think we recognize the threat is real," Neason said. "We have soldiers here that are exposed to all the hazards and dangers — and soldiers are being injured and dying as we fight this global war on terrorism. So for me, it's still very much something that's current."

For Blackwell and for three of the Schofield soldiers who were at the Pentagon on that day, 9/11 remains very personal. Their stories are below.

Lt. Col. Mike Blackwell

Now the commander of more than 800 soldiers in the Military Police Task Force in Afghanistan, Blackwell was the MP Brigade executive officer at Schofield on Sept. 11, 2001.

"I was the first one who got the call from the Emergency Operations Center at (the 25th) Division," Blackwell said. "I had to alert all of the security infrastructure for all the bases on Hawai'i to get prepared."

His brother, Chris, a firefighter with Rescue Unit 3 from the Bronx, was at the World Trade Center within a half-hour of the first plane strike, the second unit to arrive.

"By the end of the day, we knew he wasn't accounted for," Blackwell said.

The 43-year-old father of three children was never found.

"It was tough," said Blackwell, himself the father of two boys, 9 and 6. "The first whole year was a prolonged thing. It wasn't like we knew that he was gone right away. After two weeks you come to the conclusion that even if they did find him, he wasn't going to be alive."

A memorial was held in late October. A year later, Chris Blackwell's children placed their father's dress uniform and small mementos into an empty casket.

For about a year, he couldn't get his brother's death out of his head.

"You give to charity and the Red Cross and things like that. You give blood. But you still never felt like you were doing something. So here, at least I feel like I've made a contribution in some way."

The Connecticut man points to the development such as voter registration numbers for upcoming presidential elections, which "are absolutely outstanding," he said. More than 9 million Afghans are registered.

He feels he has a stronger connection to Afghanistan because "this is where the training camps were. This is where Osama bin Laden was. So it's got a much more direct link psychologically to what happened on 9/11."

Maj. Andy Preston

Now the plans officer for Combined Joint Task Force 76 in Bagram, Preston then had a similar role at the Pentagon for the war plans division of Army operations.

He was working on the third floor when the hijacked American Airlines jetliner exploded through the two floors below.

"Having never experienced an earthquake, I would expect that's about what it's like," said Preston, 37. "There was a very loud initial blast or boom and then kind of a rolling shudder through the building. You could feel the plane coming."

Smoke filled rooms through air vents. Fire alarms blared. The remains of what had been the front of the plane were below. One fire-escape door was heated and inaccessible because of burning debris on the other side. In the corridor, people were shoulder to shoulder.

"I remember thinking, even at the time, how calm everyone was. Everyone was focused, everyone was ready to get out, but there was no pushing, no yelling. It was very disciplined. Remarkable."

Preston, a 14-year Army man from Oklahoma, said he's glad to be in Afghanistan.

"I think it's very important that the people of the United States understand how big of a difference we're making over here."

Three years later, al-Qaida "doesn't have the (terrorist) training camps here, and they don't have the ability to do the things they used to do."

Today, he'll be thinking about a very different time, the dark hours of 9/11.

"I think about my family," Preston said of his wife, Gina, and his two daughters. "September 11 was a very difficult day for my family."

Lt. Col. Clarence Neason

Neason, 46, commands the 3rd Battalion, 7th Field Artillery Regiment, in Afghanistan, but his more than 500 soldiers are spread across the country in a more infantrylike role, heading out on patrols and engaging local leaders.

Taliban and al-Qaida remnants are an elusive enemy that are no match head to head with superior U.S. firepower.

"They recognize what it is that we bring to the table," Neason said from Kandahar. "There's just pockets of resistance. There's no sort of sustained, conventional fight."

Three years ago, the New Orleans man was a special assistant to then-Army Chief of Staff Gen. Eric Shinseki at the Pentagon.

At a meeting at the National War College across the Potomac when the jetliner hit the Pentagon, Neason watched as smoke billowed up, went back to the damaged building to try to help, and watched over the next nine months as it was built back up.

"Initially, looking at what happened, it was very shocking that this actually happened on U.S. soil," Neason said. "This happens elsewhere — not here, and this demonstrated that we are vulnerable, too."

The attack affirmed his commitment to the nation as an Army officer, and serving in Afghan-istan has given him a chance to use the training he received.

"It's an opportunity for us to suppress this whole terrorist threat, and get to the heart of it all — helping sustain this government," he said.

Lt. Col. (Chaplain) Larry Adams-Thompson

Every morning, Adams-Thompson attended a staff meeting at the Pentagon as Army Well Being Division Branch chief.

Two weeks before the 9/11 attack, he was moved out of the position. The aircraft that smashed into the Pentagon damaged a portion of the office, injured many of the people in it, and killed their boss, a three-star general, across the hall.

"I was just fortuitous, I guess," Adams-Thompson, 55, said. "Obviously, being a chaplain, I believe that God had his hand in that."

Uninjured, the Texas man joined the procession evacuating the building.

"When we walked out into the hallway, our group of folks tried to stay together so we could make sure we all got out," he recalled. "One gentleman came down from the third floor — we were on the second floor — who was burned pretty badly and collapsed on the floor. But there were so many people in the hallway that he was immediately attended to."

For the married father of five children, the attack brought back memories of his infantry days with the 25th Division in Tay Ninh in 1969 and 1970, during which he saw a lot of combat.

Adams-Thompson is the only 25th soldier deployed to Afghanistan who previously saw combat in Vietnam. He became a chaplain in 1983.

"I think I realized I hadn't really processed all of the things that I'd seen and experienced in Vietnam," Adams-Thompson said, "because I found myself having nightmares not so much of the Pentagon, but back with what happened in Vietnam."

Adams-Thompson said soldiers take heart from positive results in the country.

For Adams-Thompson, there's satisfaction, too.

"When you get out of the States and get over here and you see what the Afghan people have had to endure for so many hundreds of years," he said, "it just makes what we do here not only an honor to defend our country, but to be here and assist these people in their own freedom, and I experience that every single day."