This was Joe Haldeman’s first published novel. It is not in the science fiction genre he is a Grand Master of. I believe it is a thinly-veiled account of much of his Viet Nam service as a combat engineer in 1968.
It’s not a long work; easy-to-read and in the vernacular of soldiers in the thick of it, but with enough explanation for those who haven’t served.
I read the Kindle version and I believe it’s probably the paperback version. Doing a little research the original hardcover had a different (apparently longer) ending. What I read was powerful. I may ask Joe what the difference was.
I have always been fascinated by the Viet Nam War. I was too young to really understand, but grew up in the time after it ended when America had to grapple with its place in history. Haldeman wrote another novel much later called 1968, dealing with the war and its aftereffects on characters. I haven’t read that one yet.