In the narrow sense I think you are correct; in the long term deeply incorrect. There are many ways for the American public to be employed. A society built on arms manufacturing seems the least desirable to me. This is the detriment I speak of. Much of our effort and economy is wasted making guns and bombs rather than more useful and less destructive things. This industry sucks up a trillion dollars in government support annually; if it were reduced and that effort (spending) directed elsewhere we would all benefit. We might, e.g., direct it to developing fossil fuel independence and obviate the need for anyone to sell arms to Saudis.