Mike Ergo is a 23-year-old honorably discharged Marine who fought in Fallujah. A tattoo on the inside of his left forearm depicts the first insurgent he killed in Iraq. A tattoo on his right arm reads: "Born to Fight." He loves the Marines, is proud of what he and his colleagues did overseas and is on inactive ready reserve through July 2009.Yet a few weeks ago, the Walnut Creek native marched near the front of the anti-war demonstration that rolled through San Francisco. Yeah, he said, it felt odd to march among the 9/11 conspiracy theorists and socialists. Still, Ergo said he'd march again to underscore his opposition to U.S. foreign policy in Iraq and would try to bring more than the handful of Iraq War veterans who demonstrated with him last month.

But Ergo knows that the number of soldiers who publicly oppose the war is likely to remain small for now. A chief reason: Unlike the men drafted into military service during the Vietnam War, those fighting in Iraq are volunteers and feel obligated to be patriotic defenders of post-9/11 soil.

Yet a few signs of dissent are appearing in the military aside from conscientious objectors and newly realized pacificists. Last month, a career chief master sergeant in the Air Force wrote an opinion piece in the military newspaper Stars and Stripes opposing the war, and a busload of retired veterans and civilian activists toured military bases in the South, hoping to coax more support from active duty soldiers. Over the past month, more than 1,700 soldiers have signed an online Appeal for Redress -- www.appealforredress.org -- a legally sanctioned way for members of the military to oppose the war.

A couple of underground publications like GI Special at www.militaryproject.org, have sprung up online, and supportive troops have clandestinely dropped hard copies inside military barracks.

Last week, retired Marine Corps Lt. Col. Andrew Horne, who served in the Persian Gulf two years ago, rebutted President Bush's weekly radio address.

Said Horne: "The commander-in-chief has failed to properly lead the troops, and previous Congresses didn't ask the tough questions or demand accountability. The result is the mess we are in today."

These inside-the-fortress expressions of opposition are almost always prefaced with words of respect for the military, of their comrades' patriotic service to their country.

This rhetorical approach is far different from the widespread protests and defiant sloganeering of the '60s and '70s. By the Vietnam War's end, more than 100 underground newspapers were published by anti-war soldiers, and thousands of soldiers had participated in peace demonstrations. Peaceniks established a network of off-base coffeehouses in military towns, giving GIs and peace activists a place to interact casually and foment more opposition to the war.

While opinion polls today show that a majority of Americans oppose the war, "95 percent of Americans haven't been touched by the war. It's not that they don't care," said Air Force Chief Master Sgt. Jeff Slocum, who wrote the Stars and Stripes opinion column supporting the online petition against the war.

But few uniformed opponents have surfaced. Iraq Veterans Against the War, an organization for uniformed opposition, gets only 10 new members a week. The 1,700-plus vets who signed the online petition are a fraction of the 1.5 million who have been deployed in the war on terrorism.

"It would be a tremendous boost to have more active duty demonstrating," said Cherie Eichholz, a veteran and an organizer with Veterans for Peace, "because they have firsthand knowledge of what's going on over there on the ground, and they have a credibility with the public because of their service."

Eichholz, who volunteered for the Army after the Sept. 11 attacks and was discharged after being injured in training, said some vets' peace groups are changing their strategy.

Last month, she was part of a convoy of 25 activists and retired vets who toured military bases in the South as part of a trial effort to aggressively court uniformed opponents. They handed out 5,000 copies of the Appeal for Redress and got a few dozen returned in days. The document states: "As a patriotic American proud to serve the nation in uniform, I respectfully urge my political leaders in Congress to support the prompt withdrawal of all American military forces and bases from Iraq. Staying in Iraq will not work and is not worth the price." The numbers might seem minuscule, Eichholz said, but she is encouraged by the hundreds of off-duty conversations she has had with young soldiers -- so much so that her organization is planning four similar caravans to tour towns near U.S. militaryinstallations this summer.

But the limited expression of anti-war support among the military "just shows that the overwhelming majority of guys are in favor of the mission in Iraq," said Navy Lt. Jason Nichols. An information technology specialist stationed in Iraq, Nichols is asking soldiers to sign an online petition called Appeal for Courage, www. appealforcourage.org, that supports the mission and opposes the Redress appeal. "Most of them (who oppose the war) can't answer the question: So what do we do now?"

Speaking out can be costly, especially for career soldiers. Two weeks after he wrote the Stars and Stripes column, Slocum decided to retire in October, long before he had planned.

"I got to thinking that I don't know if I can continue to wear two hats," said Slocum, 41, a veteran of 21 years in the service who is stationed near Fayetteville, N.C. He began opposing the war after disclosures that the United States went to war based on faulty intelligence. His peers told him to find a way to support the war. "That would be OK," he said, "if I didn't know what I already know."

Ergo, the Marine, believes another factor is behind this reticence: Many returning soldiers are still too overwhelmed with the effects of post-traumatic stress syndrome, one of the war's signature wounds -- including him. Ergo was diagnosed with the condition shortly after leaving the service in 2005.

For months after he returned home, a never-ending clip of the men he saw die and of those he killed reeled through his mind. He enrolled in Diablo Valley College, but within months he was missing class. He'd start driving to school, then turn around, afraid of the people he'd have to deal with there.

"It was this impending sense of something big was about to happen," he said. "The feeling I'd got when we were about to go into combat. I was afraid of dealing with people who would say something against the war, or make me angry. I was afraid of flipping out and maybe hurting someone."

He began regularly seeing a counselor last fall and began feeling better. At the same time, he began to read more about the government's reasons for invading Iraq. He started communicating with vets he found on a MySpace page for the Iraq Veterans Against the War.

"It's hard enough to deal with the experiences that went on in Iraq, let alone to have opinions on it," Ergo said. "When people come back, they'd rather just move on and not remember all that stuff. And not try to live in the past.

"And if you don't live by a vet center, you might just sit around, listen to music and drink. It can definitely be a downward spiral," he said.

His opinion of the war changed shortly after November 2004, when he was involved in fierce house-to-house searches for insurgents in Fallujah. He would kick in doors and often see an insurgent shooting at him from close range. Iraqi women and children would walk down the street, and insurgents would maneuver among the citizens, using them as shields.

The tension was emotionally exhausting.

"You're spending your days driving around the highways looking for people who are hiding, and they blow you up from a mile away with a remote detonator," he said. "Or they shoot at you from a building and put their weapon down and walk through the streets. And if you kill someone, you could potentially turn that town against you whether it's justified or not."

He came out publicly against the war after returning home.

"I was turned off by the apathy of all the people in this area, Walnut Creek, and other upper-middle-class communities who thought things were going fine or are so removed from the war," he said. "Like the people I was going to school with (Diablo Valley College) were just worried about what's on "TRL," MTV's "Total Request Live" program.

Ergo plans to talk about his experience in schools and to speak before other organizations. He is not a counter-recruiter; he urges people to "do their research" before they enlist. And he understands that many active duty soldiers won't speak out.

"They don't want to be associated with a movement they see as entirely leftist or irrational or hippies from Berkeley or San Francisco," he said. "But once people see us on the news, maybe they'll say, 'Hey, that guy has a short haircut, he looks like he could still be in. He wears tucked-in shirts. He doesn't have long hair.' "

Ergo doesn't have to look far to see his own wounds from the war. The man whose face flashes in his mind is tattooed on his left forearm. It reminds him how much he and other soldiers -- and Iraqis -- have sacrificed in this war.

"I have to see it," Ergo said. "So I want everyone else to see it, too."

E-mail Joe Garofoli at jgarofoli@sfchronicle.com.

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