Quote from Immanuel Kant,
"War itself requires no special motive but appears to be engrafted on human nature; it passes even for something noble, to which the love of glory impels men quite apart from any selfish urges. Thus among the American savages, just as much as among those of Europe during the age of chivalry, military valor is held to be of great worth in itself, not only during war (which is natural) but in order that there should be war. Often war is waged only in order to show valor; thus an inner dignity is ascribed to war itself, and even some philosophers have praised it as an ennoblement of humanity, forgetting the pronouncement of the Greek who said, "War is an evil inasmuch as it produces more wicked men than it takes away." So much for the measures nature takes to lead the human race, considered as a class of animals, to her own end."