There is an undeniable conflict between "Don't be evil." and "Evil pays.". A lot of what militaries do can be best described as the lesser of two evils. Murdering people is bad, but sometimes a little murder can prevent a lot of murder. However ethically or unethically a state uses force, there's usually a lot of money to be had in supplying that state with the means of force.

Is there room for ethics in military research and procurement? Absolutely. An AI company might say, "We will help you choose the best targets when under time pressure, but we won't provide an oracle that lets you justify indiscriminate killing of civilians." An explosives factory might say, "We'll build precision missile warheads for you, but not white phosphorous or cluster munitions, because these kill civilians indiscriminately.". People working for companies that do defence work have a moral obligation to observe how their labour is used and refuse to give it if the results are unethical. It's no different from soldiers having a moral duty to refuse illegal orders.

To answer your question, I'd say that participating in the defence industry can be justifiable if you remain guided by ethics, and unjustifiable if you abandon them for money. e.g. If you're currently doing anything to help develop the IDF's Lavender or "Where's Daddy" programs, it's pretty hard to argue that you have a functioning moral compass.

It's also completely fine to say, "I don't want to deal with moral grey zones" and refuse to work for companies that do military work. You might make less money, but you'll almost certainly sleep easier.

> You might make less money, but you'll almost certainly sleep easier

Idk, there's something unethical in outsourcing ethical grey areas to other people while reaping the benefits of the peace (or war far from your home) it brings.

There is also the simple fact that predatory monsters exist. A wealthy society that demilitarizes learns the lesson Europe is now. (If Ukraine didn't have a domestic defence industry, it wouldn't have been able to fight the fight it has been able to.) Put another way, you'll sleep easier, but it's a false security, even if it's one that may last for the rest of your own life.

I'd also note that you can absolutely contribute to parts of the military where you actions are highly unlikely to directly result in anyone dying. Air-defence radars and munitions, for example, particulalry those designed to take out missiles and ballistics.

[dead]