Goodnight Saigon, by Richard Helms

 "Goodnight Saigon," by Richard Helms, in Only the Good Die Young: Crime Fiction Inspired by the Songs of Billy Joel, edited by Josh Pachter, Untreed Reads, 2021.

I have a story in this book.

This is the sixth appearance on this page by Richard Helms.  It is more war story than mystery but there is plenty enough crime to qualify.

And a riveting war story it is.  It's 1958 and soldier Owen Wheeler, for offenses unknown to him, has been transferred from a cushy assignment in Germany to a job in Vietnam training the nation's soldiers.  It wasn't supposed to be combat work "but once the black flag rose and the bullets flew, every man in a uniform was fair game."

Taking the trainees out on a long-range recon patrol Wheeler encounters deadly enemies, human and otherwise.  In the process he captures a Viet Cong soldier and brings him back for interrogation.  And that's when the story turns to crime, and gets very very twisty.

You'll want to read all the way to the satisfactory ending in one sitting.