The late, great Bill Hicks said it best:
There was nothing great about Bill Hicks. He was simply a bitter man that hated everything. What's funny is that he would despise people like you that deify him now that he's dead.
Take all that money we spend on weapons and defenses each year and instead spend it feeding and clothing and educating the poor of the world, which it would pay for many times over, not one human being excluded, and we could explore space, together, both inner and outer, forever, in peace.
This from the same man that described humanity as "a virus with shoes"
Hicks was no different from any other bi-polar leftwing cynic: swinging wildly from visions of utopia to expressing the deepest hope that a giant meteor would come and end humanity once and for all. Yes, that's some voice in the wilderness you follow.
Imagine how much good will there would be in the world if, instead of killing these people, we fed them?
We already do that to a great extent. The United States in particular gives away more aid in food, medicines, and money than anyone else in history. We do it on a massive scale. And it'll never bring about this utopia you seek. Because humanity is flawed, and despite Gene Roddenberry's own utopian ideals, human nature will never "evolve". It is what it is. The are inescapable consequences to this truth. "For the poor will always be with you", as Jesus put it, is one of them.
We could totally and completely devote our country to doing nothing but feeding and caring for the rest of the world. We could completely stand down our army and become the biggest welfare state anywhere. And it would change nothing. Because there will always be people that, no matter what you do for them, will want to kill you and take what you have, or simply kill you because they don't like what you're thinking. The ramblings of "if we just embraced peace" from people like Hicks are the ramblings of fools. We're not perfect by any means, and there's a lot of room for improvement, but I'll take having a military defend our interests while trying to help others as we can... over simply laying our arms down and hoping for the best. The former is prudent. The latter will end you, with some other guy killing you and taking your stuff.