NA Science Fiction - War based - Kill each other if acting strange

[K]

I'm looking for a short story I read in high school. I put NA in the title because of the group rule to put NA for characters in their 20s.
I remember reading this in 11th or 12th grade in my California High School.

The story is about war (in WWI? WWII?)
The details are fuzzy, but I do remember there being men trapped and having their own personal objects that they keep from the others.
I remember there being a rule that if someone acts strange/suspicious they are to be shot.

The whole thing was a trippy mind-game of guessing if others are acting strange or if the protagonist is the one acting strange.

Please, help, I've been wanting to read this for years now.

[Justanotherbiblophile]

Have you read "I Have No Mouth, and I Must Scream" and "Second Variety"?

Portions of the description remind me of these two; but neither is a good match.

[K]

Justanotherbiblophile wrote: "Have you read "I Have No Mouth, and I Must Scream" and "Second Variety"?

Portions of the description remind me of these two; but neither is a good match."

Yea, it's not a match. Thanks for trying, nonetheless.

[K]

bump. bump. bump.

[Kris]

Kimberley, were civilians or only the military/police encouraged to shot people who acted strange? Can you give gives examples of strange behaviors? What type of weapons were used?

[STU]

This reminds me a bit of Who Goes There? by John W Campbell Jr.
The movie The Thing is based on this short story.
I think it's a mixture of military and scientists in the arctic unsure of who has been "absorbed" by an alien.