well, I believe the first recorded war was around 2700 BC. Western culture and technology may contribute to us being "better" at war, but it's hard to say it's the root cause.

One could presume that, like which occurred in native american societies, and tribal cultures in Africa, people warred over natural resources.

Lion prides certainly wage war on each other for dominance and mating rites.

It's hard to say. War of some kind or the other just may be part and parcel of living on this earth.