Brad DeLong has a long, interesting post on the writings of Norman Angell, a British writer who thought that the terrible nature of modern war, as evidenced by the Great War, would result in permanent peace. The Great War is, of course, now popularly known as World War I because, alas, it had a much larger budget sequel.
John Mueller updated Angell’s thesis in the early 1990s with “The Obsolescence of Major War,” in which he noted that, like slavery, large scale war was simply beyond the pale in modern societies. So far, he, too has been proven incorrect.
We haven’t solved the fundamental problem of international relations: anarchy between states. While we have something termed “international law,” it exists only as an administrative code rather than an enforceable set of norms–especially as against major powers that find it in their interest to disobey. States have interests, the interests sometimes clash, and compromise is seen as unacceptable. Given the lack of a legitimate mediator, the military instrument of power comes to the forefront. So it has always been. We don’t seem particularly close to solving this problem and, indeed, may be further than we have been in a long time, as evidenced by the US-UK-EU-UN split on Iraq.