Just so we are on the same page, are you saying that that morality is subjective and not objective?
I was referring to the way you keep using "we" as if everyone agrees on this moral standard you're claiming. I'm quite sure people don't agree and that the moral standard is yours alone ... though you may have some select group of people who agree with you here and there.
But, to answer your question ... I think the way people choose their morals is subjective. I believe the efficacy of those morals is objective, but that point is moot given our finite abilities.
Most military gear is designed by civilians.
I would argue that is only a semantic distinction. I was careful to refer to the "average citizen". As it happens, my company supplies (among other things) military equipment and I've been involved in its design. First, the military excels at giving lists and lists of requirements to the extent that they put you in a box where very little designing actually occurs. Further, what design does occur is done by specialists who focus on military equipment. We have a special division that focuses only on military equipment, and my involvement was "subcontracted" by them so to speak. As such, given that the "civilians" who do this design work are military specialists, they are not "average citizens". I wouldn't hire you to design our military equipment given what I know of your background.
What the military finds relevant doesn't change the facts about whether it is arbitrary.
Neither will they consult you, so your judgement of what is arbitrary is irrelevant. It would only become relevant if you somehow became involved with the design or use of military equipment. [edit: In other words, your method of determining what is arbitrary is starting to appear ... umm ... arbitrary.] As such, I think it is important that we distinguish what is arbitrary from what is disagreeable. Maybe you objected to the Iraq War, etc. Maybe you're a passivist. That wouldn't make military decisions arbitrary.
So, is there any extent to which you would trust military experts. Suppose they have demonstrated items 1 through 9 and you agree they aren't arbitrary. Would you be willing to accept item 10 as not arbitrary based on a track record? Or are you going to insist that every single item must be judged on its own in order for you to assent?