Explorers And Engineers

In Star Trek: Discovery, a Star Fleet spaceship crew member does not want to fight, claiming that he and his colleagues are explorers, not soldiers. Nevertheless, their ships are armed because the galaxy contains nasty surprises like the Klingon Empire.

In Poul Anderson's The Snows Of Ganymede (New York, 1958), the politically neutral Order of Planetary Engineers are soldiers only:

"...in man's finest war, the fight of all men against a blind and indifferent nature which had brought their kind forth without caring." (Chapter 1, p. 6)

Nevertheless, in their Archimedes Academy (the "Abbey") on the Moon:

"There were also guns and arsenals and launching racks for guided missiles, but they were hidden, and nothing was said about them. They had been stocked against a day of trouble which might or might not come." (Chapter 2, p. 9)

When human civilization does face an interstellar threat, it is from the anti-technological Alori, very different from the militaristic Klingons.