He was an American serviceman based in Vietnam during the war.

他是一名战争期间在越南基地服役的美国军人。

《柯林斯英汉双解大词典》

At that time, serviceman with uniform could be seen at any moment who wanted to get a lift to go home on the highway of American.

当时，在美国的高速公路上，随时可见穿着制服的军人搭别人的车回家。

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The fate of an American serviceman should not become the football of a global popularity contest or of megalomaniacal political agendas.

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But I would tell you that I can't imagine -- I obviously wasn't here in 2008, when President Bush issued a similar apology after there was an American serviceman who had damaged a religious document of some kind.

WHITEHOUSE: Press Briefing by Deputy Press Secretary Josh Earnest

Vaughn Taylor, who has long represented Robert Garwood an American serviceman in Vietnam who collaborated with his captors in order to survive his incarceration which continued until 1979, emphasized that Garwood has consistently reported having seen hundreds of other U.S. prisoners held against their will by Hanoi.

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