Did we forget about Haiti and Japan already? Both were relief efforts that the US military was heavily involved in.
Granted, these two examples are NOT all encompassing, but you also can't deny that they were done for the greater good. And they are not, by any means, the only two examples of a humanitarian effort...
What about all the job and technical skills people walk away with after only a 4 year tour with the military? Instead of being some grass smoking, occupy wall street, patchoulie scented hippy and living for free off of the very establishment that they condemn?
We can go back and forth, point and counter point all day, and it will get us nowhere. But to say that nothing is productive about the military, and that no good comes of it, is blatantly wrong. However, please do not mistake me for saying that the military is some perfect and golden god-like society. It has its fair share of bad apples at the top, and throughout the ranks. But average Joe in the ranks, is just following orders, and trying to do what he perceives to be the right thing.
Tl;DR? tough.. there is no short answer.