A U.S. soldier who left his unit in Iraq rather than fight for what he called an "oil-driven war" is claiming that he's a conscientious objector who believes the war is unjust and that he's upset over civilian deaths.

Staff Sgt. Camilo Mejia (search), 28, of Miami Beach, Fla., faced a court-martial Wednesday. If convicted of desertion by a military jury at Fort Stewart, Ga., he could find himself in prison for a year and may receive a bad conduct discharge. His attorney asked a military judge Wednesday to dismiss the charge, saying the infantryman was entitled to leave the military because he is a citizen of Costa Rica

The Florida National Guardsman left his unit in Iraq in October on a two-week break to the United States. He was gone for five months before turning himself in to the Army in March.

"When I saw with my own eyes what war can do to people, a real change began to take place within me," Mejia wrote in his testimony about why he didn't go back to Iraq. "I have witnessed the suffering of a people whose country is in ruins and who are further humiliated by the raids, patrols, curfews of an occupying army. My experience of this war has changed me forever."

Aside from the court-martial process, Mejia hopes to obtain status as a conscientious objector (search).

A conscientious objector has to prove a religious, ethical or moral opposition to war when applying for a discharge or for non-combat service, according to the Center on Conscience and War (search). If an applicant is not accepted, the refusal to fight could result in a court-martial.

The Selective Service System (search) provides manpower to the armed forces in an emergency and is commissioned to run an alternative service program for people classified as conscientious objectors during a draft.

According to that U.S. agency, beliefs that qualify someone to get conscientious objector status may be religious in nature, but they don't have to be. Beliefs also may be moral or ethical.

A person's reasons for not wanting to participate in a war "must not be based on politics, expediency, or self-interest," according to the agency, and the U.S. serviceman or woman's lifestyle prior to making his claim must reflect their current claims.

"It's really too late for him to claim conscientious objector status" since Mejia had already been in Iraq for a year, said Andrew Napolitano, a former judge and Fox News' senior judicial analyst. If the conscientious objector application was approved, Napolitano said, "It would allow soldiers to decide when they fight."

"Quite frankly, if a soldier becomes a conscientious objector on duty, he's expected to stay on duty and put his application in," said William G. Eckhardt, a military law expert who teaches at the University of Missouri Kansas City. "COs crawl all over the battlefield … save people lives, they just don't carry weapons."

One problem is that by volunteering to enter the service, Mejia basically said he wasn't objecting to the idea of war.

"When you enlist, one of the boxes you check off on the enlistment contract is, 'I am not a conscientious objector,'" Todd Ensign, one of Mejia's lawyer, told Foxnews.com. "When you join the military today, you are saying you are not a conscientious objector … [but] that was the case when he [Mejia] was 19 years old … over nine years, often people's minds change. The fact that the military has a CO process reflects their recognition of that."

Mejia claims that during his time in Iraq, he witnessed and took part in things that made him a conscientious objector. The guardsman made his claims before the recent uproar over prison abuses at the Abu Ghraib (search) prison outside Baghdad.

"Its [prison abuse] relevancy to conscientious objector is there — tangentially," Eckhardt said. "I suspect that its greatest use would be for the discretion on the part of the government … bottom line is, for the desertion charge, it's probably much more relevant."

In his objector application, Mejia said Iraqi detainees were kept blindfolded and troops were ordered to use sleep-deprivation tactics to aid with interrogations. He said prisoners were kept awake for up to 48 hours at a time and were often yelled at or made to sit and stand for several minutes.

"When these techniques failed, we would bang on the wall with a huge sledgehammer ... or load a 9 mm pistol next to their ear," Mejia wrote. "The way we treated these men was hard even for the soldiers, especially after realizing that many of these 'combatants' were no more than shepherds."

During his time away from the military, Mejia tried to obtain a discharge based on the fact that he is not a U.S. citizen — he's a permanent resident with a green card and Costa Rican citizenship. The Army normally limits non-U.S. citizens' service to eight years; Mejia learned that the time limit was suspended during the war on Iraq.

According to the American Friends Service Committee (search), during the 1990-91 Persian Gulf War, an estimated 2,500 U.S. military personnel applied for conscientious objector status but only 270 were successful.

Many believe that conscientious objectors can object to a particular war. Others consider objection to war on any grounds — not just "moral or religious principle" — to be conscientious.

The conscientious objector application process is long so it may not work in Mejia's favor.

"He could get convicted, go to jail, do his time and at the same time, the CO application process could be continuing," Ensign said. "The CO process is a slow and laborious route."

According to the Center on Conscience and War, two out of five conscientious objector applications were decided upon this year. In 2003, 31 out of 60 were decided upon.

In 2002, of the 2.7 million men and women in the U.S. active and Reserve forces, 29 were discharged as conscientious objectors, according to the center.

During the 1993 Gulf War, 111 conscientious objectors were discharged; in Vietnam, approximately 170,000 of the 2.15 million drafted were discharged; during the Korean War, 4,300 were discharged; during World War II, about 4,200 were discharged; and during World War I, about 3,800 were discharged.

Ensign said that given these numbers, it's not very likely granting Mejia conscientious objector status will set a precedent.

"It could happen but the fact is, and this is kind of surprising, that CO applications are way down," Ensign said, noting that five to seven years ago, out of the 500 to 800 conscientious objector applications filed, about 60 percent were successful.

"I have much more confidence in the American soldier than that," Eckhardt added.