"I believe that most men who have been to war would have to admit, if they are honest, that somewhere inside themselves they loved it too, loved it as much as anything that has happened to them before or since. To love war is to mock the very values we supposedly fight for. It is to be insensitive, reactionary, a brute. But it may be more dangerous, both for men and nations, to suppress the reasons men love war than to admit them. Alfred Kazin wrote that war is the enduring condition of twentieth-century man. He was only partly right. War is the enduring condition of man, period. Two million Frenchmen and Englishmen died in muddy trenches in World War I because a student shot an archduke. The truth is, the reasons don't matter. There is a reason for every war and a war for every reason.

For centuries men have hoped that with history would come progress, and with progress, peace. But progress has simply given man the means to make war even more horrible; no wars in our savage past can begin to match the brutality of the wars spawned in this century, in the beautifully ordered, civilized landscape of Europe, where everyone is literate and classical music plays in every village cafe.

Like all lust, for as long as it lasts it dominates everything else; a nation's other problems are seared away, a phenomenon exploited by kings, dictators, and presidents since civilization began. The love of war stems from the union, deep in the core of our being between sex and destruction, beauty and horror, love and death. War may be the only way in which most men touch the mythic domains in our soul. It is, for men, at some terrible level, the closest thing to what childbirth is for women: the initiation into the power of life and death. It is like lifting off the corner of the universe and looking at what's underneath. To see war is to see into the dark heart of things, that no-man's-land between life and death, or even beyond.

It is no accident that men love war, as love and war are at the core of man. It is not only that we must love one another or die. We must love one another and die. War, like death, is always with us, a constant companion, a secret sharer."

http://public.wsu.edu/~hughesc/why_men_love_war.htm