It's been done before. Look up Tomoya Kawakita. He was an American born to Japanese parents. He moved to Japan and WWII broke out he worked for the Japanese government using American POWs for manual labor.
When he returned to the US after WWII, he was recognized in public by a former POW who told the FBI. Kawakita was arrested, found guilty of treason, and sentenced to death. His sentence was later reduced to life in prison. Then in the 60s JFK allowed him to be released on the condition that he never return to the United States. He was flown to Japan where he quietly lived out the rest of his days. During his exile he did request permission to briefly return to the US so he could visit his dying parents, but the request was denied.
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