SEOUL, South Korea - The young dentist was uncuffed and led to his seat in the courtroom. A few rows back, his mother watched motionlessly, her hands gently clasped together as if in prayer.

Jeon Seong-Jin is being punished for a crime that is not a crime at all in most of the world. A Jehovah's Witness, he has refused to become a soldier in South Korea, where all able-bodied male citizens are required to serve about 21 months in the army.

More than 660 conscientious objectors have been jailed each year in South Korea, on average, from 2004 to 2012, far more than any other country. Eritrea is second, but imprisoned only about 50 conscientious objectors last year, according to the official website of Jehovah's Witnesses. Members of the religion refuse military service because they believe the Bible forbids warfare.

Even where conscription still exists, governments often allow conscientious objectors to serve their countries without bearing arms, but not in South Korea. Jeon began his 18-month sentence in 2012 and expects to be released this March.

Even behind bars, Jeon continues a legal battle. He appeared in court last month as part of his lawsuit demanding that conscientious objectors be given alternative service instead of prison. The court rejected his case last week.

"Seong-Jin can use his medical expertise to serve his country instead of being in jail," says his mother, Yoon Hyun-Jin, wiping away tears at last month's trial. Her 26-year-old son was cuffed again, bound in ropes and taken back to prison.

South Koreans who refuse to take up arms often find little support from their countrymen and have trouble finding work after their release from prison. Hundreds of thousands of soldiers face each other along the Demilitarized Zone separating North and South Korea, one of the most heavily fortified places in the world. The 1950-53 Korean War ended with an armistice rather than a peace treaty, leaving the peninsula technically at war.

"It's reasonable to jail people who don't go to the army," said Jeong Won Seok, a 32-year-old programmer. "Who wants to go the army, anyway? Most go because they have to and sacrifice a lot of freedom for it. What kind of conscience outweighs the sacrifice made by those who serve in the army?"

South Korea is better known for its catchy K-pop songs, tech-savviness and economic growth than it is for the more than 17,500 conscientious objectors who have been imprisoned since 1950. Most are Jehovah's Witnesses, who number about 100,000 in this country of 50 million and often face stigma in its largely conformist society.

More than 50 men have refused to serve in the past decade because of nonreligious personal beliefs or political reasons, including 25-year-old Kim Dong Hyun.

"Right now, I only have two choices: military or prison. Of the two, I think prison is the more peaceful choice," Kim said. "At least in prison I don't have to train to kill."

Kim, like Jeon, was sentenced to 18 months, which today is a typical sentence for conscientious objectors in South Korea. Under South Korea's military-backed dictatorship in the 1970s and 80s, imprisonment lasted up to seven years.

The United Nations Human Rights Committee criticizes South Korea for not recognizing conscientious objectors and failing to give them alternatives to military service- a violation of freedom of thought, conscience and religion recognized in the International Covenant on Civil and Political Rights. South Korea has been party to the covenant since 1990, but the country has made no major changes to stop the jailings.

Seoul's Defense Ministry cites North Korea's security threat as a key reason for not recognizing conscientious objectors. In 2010, a South Korean warship sank in the Yellow Sea after an alleged North Korean attack, killing 46 sailors. The same year, four South Koreans were killed by North Korean shelling of a coastal island. About 28,500 American troops are deployed in South Korea to help deter North Korean aggression.

Each year, South Korea conscripts more than 26,000 men and sends 300 to 800 conscientious objectors or draft evaders to prison, according to Seoul's Military Manpower Administration, which handles conscription matters. The government doesn't distinguish draft evaders and conscientious objectors like Jeon.

Society's caustic view of conscientious objectors has much to do with draft-dodging by celebrities and society's privileged. The country has known sons of rich and powerful men bribing or cheating their way out of drafts. In 1997, presidential hopeful Lee Hoi-chang lost both votes and integrity after his two sons were accused of draft evasion.

Other men have damaged joints and ligaments and even feigned insanity to avoid the army.

There are legitimate ways to avoid becoming a soldier: South Korea allows alternative civil service for men with minor disabilities, special skills or high academic achievements. Even men who cover their bodies with tattoos get alternative service because the army rejects them. But attempts to allow alternative service for conscientious objectors fell apart in 2008.

Seoul's Defense Ministry said it scrapped the proposal because two-thirds of the country opposed it in opinion polls. Proponents of alternative civil service say such rights shouldn't be curbed by public opinion.

The consequences for conscientious objectors go beyond prison. Two years ago, the government sent a notice to Jeon's hospital to fire the dentist or be charged with violating the Military Service Act, which prohibits employers from hiring draft evaders. Jeon can continue his medical practice after his release but won't be able to work in the public sector because of his criminal record.

Lee Jo-Eun, an activist at Seoul-based group WithoutWar, which organizes anti-war protests and workshops for conscientious objectors, said they are often shut out of jobs at big companies and in the public sector, and often have to settle for part-time work.

Jeon has said in court that he felt he had no choice but to reject military service. Two years ago, he told judges that even as a child, he couldn't bear the guilt he felt playing with a toy gun.

His beliefs haven't wavered in prison. He began his unsuccessful appeal last month by telling judges, "My conscience has never felt more comfortable."