I try to stay practical about it. A screwdriver manufacturer is not an arms dealer. But if your work only has value in the violent world of war, then I think it’s worth asking yourself if you’re comfortable with that. I don’t always disparage people that are, even though I certainly couldn’t stomach it.
My rule of thumb is to ask whether the defense industry is the only customer for the product. The company I work for does sell some to defense, but the products were not designed with defense as the primary purpose. It still doesn’t feel great to me, but I’m finding it increasingly difficult to avoid defense funding nowadays.
Why should my tax dollars be used to bail out someone who bought a multimillion dollar home in a high risk area? Why should home owners get all the profits from owning but get to skirt the risks?