The fact of the matter is that war is a basic function of human societies, as much as food production or waste disposal. Unsurprisingly, it thus taps the ingenuities of the society in the same way as those other areas. It both benefits from ingenuities intended for other purposes, and results in inventions itself that can be used for other purposes. And for better or worse, war is a great way to get the public to support R&D spending. DARPA could not be what it is without being a part of the DOD. See: <a href="http://tech.mit.edu/V114/N29/dod.29n.html" rel="nofollow">http://tech.mit.edu/V114/N29/dod.29n.html</a>, <a href="http://web.mit.edu/annualreports/pres07/12.00.pdf" rel="nofollow">http://web.mit.edu/annualreports/pres07/12.00.pdf</a>, <a href="http://en.wikipedia.org/wiki/DARPA_Grand_Challenge" rel="nofollow">http://en.wikipedia.org/wiki/DARPA_Grand_Challenge</a>.<p>And let's face it, its something you benefit from tremendously. You do not want a society in which the US does not have the power to kill everyone. That is a society in which your lifestyle is not as nice as it is now. Indeed, with the challenges we face in the coming century (oil, water scarcity, etc) as well as the ascension of India and China as world powers, our ability to kill people is going to be more important than ever.