A soldier is a yahoo hired to kill in cold blood as many of his own species, who have never offended him, as possibly he can.

Jonathan Swift (1667–1745) English writer and churchman

Gulliver’s Travels, Part 4 “Voyage to the Land of the Houyhnhnms,” ch. 5 (1726)
    (Source)

Following a long litany of the causes of wars in Europe, the number of such causes leading to the "trade of a soldier" being held "the most honourable of all others," for the above reason.