It matters a great deal, though you might imagine otherwise: my company makes bombs.

I feel that I make a difference with my work. I can see the results in the news.

Being unethical would include things like selling duds, billing the customer for time spent on other projects, colluding with competitors to raise bid prices, bribing the customer's people to choose us, stealing plans from a competitor, hiring unqualified family, and choosing subcontractors based on bribes.