If your company sells earplugs to a military like NATO or the IDF, do you share moral responsibility for how they are used?

This is a question that has degrees to it; it is not a black-and-white answer. The first thing, of course, is that as a Christian you refuse to take jobs that are directly ordered to evil, like making IUDs or abortion instruments. But then you reach situations where a company makes ninety-nine percent good products and one percent that is used for evil, and you have to decide. You could boycott, and in principle you could, but you reach a point where the society is so bad that every company funds abortion or immoral causes, and if you boycott them all you end up living out in the desert by yourself. So you live in the world but are not of the world, and when the opportunity comes you do not support them directly, but you will still sometimes have to buy from companies that fund these things and there is really nothing you can do about it. With the earplugs you are not witnessing a murder; you are only speculating that they are going to throw bombs, so it opens up whether it is legitimate to advance your argument speculatively. In the end it boils down to what each man thinks in his conscience, as long as that conscience is informed and can spit out the facts on both sides and then make an intelligent, logical, moral decision he is comfortable with. Romans 14, about meat offered to idols, gives us that same principle: even when you are right in your moral judgment, you may relax your position for the sake of love of your brother so that you do not make him fall.