In truth, the inclination of humans to fight unnecessary wars is evidence that the human species is borderline crazy.
But of course most people reject the idea. Who likes to admit that they're borderline crazy?
Maybe the most powerful modern evidence of human craziness was the First World War, also known as the Great War, a war fought for the sake of myths about heroism and masculinity, the myths promulgated by war makers maybe acting on behalf of profit-seeking munitions makers. Someone always profits from war, but that's neither interesting nor significant. What is both interesting and significant is how masses of people are manipulated by their culture or by those in power to go to war and get killed. In the Great War of 1914-1918, large masses of people were manipulated to march into a meat-grinder killing machine -- and that is interesting.
It's typical of unnecessary wars that forever and ever historians are trying to figure out why they happened. This reminds one of the TV broadcasters and journalists who, after a mass killing by some psychotic young man, scratch their heads and puzzle about why the mass killing happened.
The mass killing happened because the young man was crazy -- and given a state of madness it makes no sense to look for "reason" when madness means without reason. There are always interior motives in the minds of psychotics -- but the motives are not reasonable.
And neither were the motives of the Great War reasonable.
Now on the 100th anniversary of the beginning of the Great War appears a new edition of a fascinating and well-written account of the social origins and context of that war -- and maybe by implication of some other unnecessary wars.
Thunder and Twilight: Vienna 1913-1914 by Frederic Morton. 391 pages. Da Capo Press. 2014 (paperback edition).
At the end of the book, in an Afterword, Frederic Morton sums up the craziness of current warfare -- especially the warfare of suicide bombers:
Contemporary warfare, then, is best practiced by the professional serial killer. It has ceased to be a national undertaking serving a common mission. It is not governed by any Geneva Conventions observed by both sides. Its parameters are not clearly defined in either time or space. It does not signal its start with a declaration of war, nor its end with a truce, an armistice, or a surrender. Its front line can erupt anywhere, at any moment, cutting right through a marathon, an office tower, or a Muslim wedding.
About the Great War, Frederic Morton sums it up with a penetrating insight: "The leaders didn't instigate the Great War -- their subjects demanded it... The streets echoed with cheers."
Indeed, they cheered. Ten million people killed in a fit of popular madness.