Human nature is not an apology for war. It is more about self awareness. We as humans, all have the seeds of war in us but war isn't always the result. We all have a revulsion to war. Human have not found war to be any more revolting than our ancestors. The majority of the population has never wanted war even when we were mere tribes. War is always a game of perceived cost and gain. Even Hitler would have avoided war to take the Western USSR without war if he could have. So, it is not war that is "human nature", it is lust for power, space and resources that is human nature. Most likely this is due to evolution of our species, after all the strongest competition in nature is actually within the species not between other species. When we were starting out, the tribes that were most ambitious and aggressive would have undoubtedly overrun and destroyed those that weren't. It was beneficial to lust for power over resources then, and it is today. This doesn't mean we love to go to war, most of us have always hated war from the time we were using stone tools, but it does mean that we all have the capacity to engage in wars and we will when the benefit outweighs the cost. Stating that war is a reality of the human experience doesn't mean that I am rooting for war, it just means that I understand that it is a part of life. It has a role in shaping who we are, life is the combination of the beautiful and the ugly ( all newborn babys, will eventually be rotting corpses at some point, tornados are beautiful... and deadly, etc. etc. in nature, destruction often is the prelude to new life). This doesn't mean that we shouldn't try to reduce war either, it just means that I realize that there will always be cases where war will be unavoidable. The world is an extremely violent and brutal place with or without humans. War has been with us from the begining, our books and movies are filled with some form of warfare or another. As long as we love conflict (which we all do, even the most peaceful of all pacifists) we will have wars, but we will also have peace, yin and yang.