Military science fiction is a sub-genre of science fiction for which the principal characters are members of a military service and an armed conflict is occurring, often in space or on a planet other than Earth excerpted from Wikipedia.
- tag wiki excerpt
However, these questions (1) (2) (3) (4) (there are more, just not looking now) are using this tag for questions about an army. Should this be warfare? Update: They now no longer have this tag. Thanks @rand al'thor ♦!
And if so, what should military-sf be used for?