How does a soldier become a peace activist?

For Charlie Clements, the answer lies somewhere between the lines of a 40-year-old military document that he keeps to this day.

“It says I’m 10 percent mentally disabled,” Clements said with a smile last week. “My protest was quite a silent one in some ways – I went quietly into the night.”

Clements, 64, is executive director of the Carr Center for Human Rights Policy at the Harvard Kennedy School.

He’s also one of 300 or so military veterans who will march through Portland’s Old Port this morning to mark the 25th anniversary of Veterans for Peace, which has grown to more than 6,000 members nationwide since its founding here in Maine back in 1985.

Military service does different things to different people.

Some wear it for a lifetime as a badge of honor, weaving their war stories more deeply into their very identity with each retelling.

Others tuck it away in the closet and rarely, if ever, talk about it again.

Then there are these vets, almost all decades removed from their days in uniform, who spend their gray-haired years marching not to the sound of a military band, but rather to the lyrics of anti-war protest songs.

Each, of course, has his or her own story. For Clements, once an Air Force pilot who flew more than 50 missions in Southeast Asia before deciding one day he couldn’t anymore, it begins as a 17-year-old cadet at the U.S. Air Force Academy in the mid-1960s.

“The dominant thought in my class was, ‘We hope the war doesn’t end before we get there,’ ” Clements recalled as the Veterans for Peace conference got under way Thursday. “Because wars are where young men test themselves, they are where young officers make their mark, they are what we were trained for.”

Upon earning his commission as a second lieutenant, Clements enrolled with the Air Force’s blessing in a graduate astronautics program at UCLA. He could have sat out the Vietnam War with his nose in a book, but he decided eight months into the program that he had a duty to serve in Southeast Asia.

He remembers walking in uniform past protesters at UCLA in the fall of 1967 – back in those early days of the anti-war movement, the protesters would just stand silently with their signs while he and his comrades passed by.

“I remember thinking very clearly that I knew much more about the world than these people did, that this was their right to do this,” he said. “And that I would go to Vietnam and defend their right to do this because I have a better understanding of this threat that faces us.”

CHOSE TO PILOT TRANSPORT PLANE

He also knew he didn’t want to kill anyone. So, upon graduating from flight school, he chose to pilot a C-130 transport plane rather than an assault aircraft and, with the war at full tilt, departed for Vietnam in August of 1969.

“What (the C-130) afforded me was a vast opportunity to see the war from different perspectives,” Clements said. “And with these experiences, I began to have encounters that gradually lifted the scales off my eyes.”

He once watched then-President Richard Nixon insist on the Armed Forces Network that the United States had no military presence in Laos, when he knew for a fact that C-130s just like the one he flew were ferrying personnel and supplies to secret U.S. bases there.

“Before that, it had never occurred to me before that the president would actually go on television and lie,” Clements said.

He once transported a group of 60 Viet Cong prisoners from one location to another – he was struck not just by the hatred in their eyes whenever they looked at him, but by an intensity, a sense of purpose that he rarely saw among young American GI’s.

GETTING THE BODY COUNT RIGHT

He once showed up at a morgue to pick up the body of a soldier killed in action. “You can’t have him today,” a sergeant told him. “The body count’s not right and we have to hang onto him for a few days.”

Known for his sharp intellect, Clements once was asked by his higher-ups to write a history of the Low Altitude Parachute Extraction System by which C-130s delivered ordnance and supplies without actually touching down. The so-called LAPES procedure didn’t work well. That didn’t matter.

“I soon realized they were going to record this the way the Air Force wanted it recorded,” he said. “Not necessarily the way the pilots perceived it was happening,”

Then there was Cambodia.

In the spring of 1970, Clements flew a top-secret delegation of State Department officials to Phnom Penh – he was told at the time it was for an off-the-record meeting about securing a portion of the Ho Chi Minh Trail that passed through that country.

Only later would Clements learn the meeting was actually to plan the overthrow of Cambodia’s Prince Sihanouk – a precursor to the invasion of Cambodia launched that May. As he flew troops into Cambodia the day before the invasion began, he found himself consumed with anger.

“I’d had this rationale that I wasn’t killing anybody, that I was an innocent of sorts,” he said. “But throughout that day I began to understand that I was very much a part of the machinery of war, that I was greasing the skids of war. And I decided what I was being asked to do was immoral.”

He asked for and received an emergency medical leave home. And when he told his stateside commanding officer that he could no longer fly missions in Southeast Asia, he was sent to an Army medical facility for what he thought was a routine psychiatric examination.

Upon his arrival, a hospital nurse handed Clements a set of pajamas.

“No, you don’t understand,” he said. “I’m staying over at the officers quarters.”

“No, you’re staying here,” replied the nurse. “This is a closed psychiatric ward and you’re not leaving.”

There he remained, without visitors or telephone privileges, for weeks. And six months later, after refusing an offer to have his record sanitized if he’d just go back to Saigon and resume flying, the Air Force quietly declared him 10 percent mentally disabled and gave him an honorable discharge.

PUTS MEDICAL SKILLS TO USE

Clements would go on to become a physician and combine his medical skills with human rights work in Central America, where he spent the early 1980s treating victims of the civil war in El Salvador (many wounded by the same U.S. military aircraft in which he once trained). It was there, in 1985, that he met and joined the founders of Veterans for Peace.

He also later served as president of Physicians for Human Rights, traveling to Sweden in 1997 to accept the organization’s Nobel Peace Prize for its efforts to ban land mines.

And now here he is in Maine, one of a small battalion of gray-haired veterans who emerged from war convinced that there has to be a better way.

Clements knows that some perceive Veterans for Peace as a ragtag group of radicals bent on tearing down the same country they once took an oath to protect. He also knows that perception could not be further from the truth.

Even now, he said, he has nothing but “empathy and respect” for those currently serving in the military – not to mention the families who have endured two, three, four or more deployments to Iraq or Afghanistan.

“I think our military is, more than ever in my lifetime, separated from the rest of society,” Clements said. “There’s a gulf between the ordinary civilians in our country and the military. We’re fighting two wars, but nobody (outside the military and their families) feels like they’re making any sacrifices.”

Time will tell whether the aging Vietnam veterans who now dominate Veterans for Peace will be replenished in the coming years with soldiers equally disillusioned by their service in Iraq or Afghanistan. Clements’ experience tells him the transition from the battlefield to the protest march often takes years, not weeks or months.

He’s also come to expect that as he and his comrades parade through downtown Portland this morning, some on the sidelines inevitably will call them a disgrace to the uniform they once wore.

But that piece of paper – the one that all these years later still labels him 10 percent out of step with the powers that once were – leaves him no choice.

“You don’t do this because of what people will think,” Clements said with another anything-but-angry smile. “You do this because of something inside you that compels you to speak your truth.”