Why was Charles Jenkins dishonorably discharged from the US Army in 2004 ?

Charles Robert Jenkins (1940-2017) served in the US Army in South Korea from 1964 to 1965. On the evening of January 4 or 5, he crossed into North Korea and surrendered hoping to be sent to the Soviet Union and then back to the USA.

In 1980, 40 year-old Jenkins was introduced to 21 year-old Hitomi Soga, a Japanese nursing student who had been abducted by North Korean agents in 1978, along with her mother. Soga's mother was never heard from again, and Soga was "given" to Jenkins. Thirty-eight days after meeting, they were married. They had two daughters, Roberta Mika Jenkins (born 1983) and Brinda Carol Jenkins (born 1985).

In 2002, North Korean leader Kim Jong-il confirmed that North Korea had abducted Japanese citizens and surviving abductees were allowed to travel to Japan, including Jenkins' wife. The visit was intended to last for a week, but the Japanese government chose not to return them and negotiated for their families to join them in Japan. After assurances of protection from the Japanese government, he traveled with his daughters to Japan arriving in July 2004. Japan requested a pardon for Jenkins which the U.S. declined. Jenkins reported on September 11, 2004, to Camp Zama in Japan and pled guilty to charges of desertion. He was sentenced to 30 days' confinement, received a dishonorable discharge, loss of all pay & benefits and was reduced in rank to private.

He died in 2017 aged 77 in Japan.