War, sometimes, is the tool to solve problem of population explosion
Overpopulation can be solved by education. When people are educated, they won't have as many children. The fact that a half of the world does not receive good education is saddening. If all that money we spent on wars went towards developing the world as a whole, we would be far more united and our population situation will be far better than it is now. Also, war does not exactly expel populations rather it creates baby boom periods after millions have been killed and in a few decades the population increases more than it was pre-war. It is definitely not a good way to control population.
But like he said that is not the only case where war is used. Also useful to control society and distract people. People afraid of their neighbors are easier to control. War is also useful to steal money and resources from the population. From the country being attacked and the one attacking. Instead of investing the money in development it can go to the pockets of some businesses. Military contractors, weapons manufacturers, companies to rebuild after the war, etc. "War is a racket."
The sad thing is, war has become somewhat like a game. We even have RULES for war 
this is total madness. It's like making rules for stealing, it does not make sense.
this is total madness. It's like making rules for stealing, it does not make sense.Better some rules to limit it than none. But it's true that they are mostly used by the stronger countries against the weak.