first and foremost, that song is great...
now lets get crackin...
war boosts the economy by giving people in war factories and creating weapons and selling them, but thinking long term, how the hell does that help anyone? all the tax money will go for buying guns and reaserching new ways to kill, instead of helping the poor and educating the youth, and all they will learn is "go there, kill him, bomb that" and that wouldnt help anyone at all. instead of wasting money on wasting people, nations should take that money and give it to reaserch for saving the planet and long term to colonize the moon and planets.
overpopulation is a joke. there are HUGE places where people dont live like deserts for instance, and what i said before about reaserch, how about reaserching ways to settle on the remaining places on the earth instead of killing people to make more room in the space we already have...
finally, every human being is first a human being (dah), and you cant morally say that killing people is ok (even in cases of rapists and murderers.... locking them for a life of solitude would be more effective then realesing them from their life, dont you think?). think about this: every human has a mother and a father, who care for them (most of the times only, sadly), friends, and in the cases of older people, children which they raised and love. every one has a childhood, whishes, things they like or dont, and hopes, and no one has absolutly NO past.
also, when you kill a man, you take away his future from him... think about that.