In 1965, Charles Jenkins, a young U.S. Army sergeant stationed at the Demilitarized Zone in South Korea, made what he described decades later as the biggest mistake of his life: He got drunk, deserted his post and crossed over to North Korea.

Jenkins spent the next four decades as a Cold War trophy of Pyongyang and the last years of his life — after being freed in 2004 — on a small, isolated island in Japan with his wife, Hitomi Soga, a Japanese citizen who had also been freed after being abducted by North Korean spies in 1978.

On Tuesday, Japan's NHK broadcaster announced that Jenkins had died at age 77. The cause was not immediately announced.

Born in Rich Square, N.C., Jenkins dropped out of school at age 15 to sign up for the Army. However, it was not until years later, at age 24, after his second posting to South Korea, that he made the decision that changed his life. In a 2006 interview with The Independent, he called it "the biggest mistake I ever made."

"I know I was not thinking clearly at the time and a lot of my decisions don't make sense now, but at the time they had a logic to them that made my actions seem almost inevitable," Jenkins wrote in 2008 in The Reluctant Communist: My Desertion, Court-Martial and Forty-Year Imprisonment in North Korea.

He said he thought he would be handed over to the Soviet Union and eventually returned to the U.S. in one of the semi-regular prisoner exchanges that were a fixture of the Cold War.

"I was so ignorant," Jenkins told The Washington Post in a 2008 interview, describing his life in North Korea as like living in a "giant, demented prison."

For the first eight years in North Korea, it was a literal prison: He was held in a small room with three other American defectors. They were forced to memorize the works of North Korean founder Kim Il-sung – earning a beating for any error.

(It was announced in August that fellow deserter James Joseph Dresnok, who crossed the border three years before Jenkins, had died the previous year "pledging loyalty to the 'great leader Kim Jong-Un,' his sons said," according to The Telegraph)

Jenkins later acted in propaganda movies and taught English to North Korean spies and military cadets.

In 1980, he says he was "presented" with Soga and forced to marry her, but that the two later fell in love. North Korea eventually acknowledged its program of kidnapping Japanese citizens. In 2002, Pyongyang released Soga, who returned to Japan. Two years later, Jenkins and the couple's two daughters were allowed to join her.

After his release, Jenkins served 25 days in a U.S. military brig and was debriefed for two months about his knowledge of the secretive regime and its sensitive installations.

But even in his final years on Sado island, Jenkins never stopped looking over his shoulder.

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