What sparks wars? The will to power, the backbone of human nature. The threat of violence, the fear of violence, or actual violence, is the instrument of this dreadful will. You can see the will to power in bedrooms, kitchens, factories, unions and the borders of states. Listen to this and remember it. The nation state is merely human nature inflated to monstrous proportions. QED, nations are entities whose laws are written by violence. Thus it ever was, so ever shall it be.