"Tales From the Venia Woods," which is part of Robert Silverburg's "Roma" series of short-stories, espouses an unusual view on the merits of Empire (or some sort of overarching governement). To make sense of what I'm saying here, I should first note that the "Roma" series takes place on an alternate earth where the Roman Empire never really fell, and now covers the entire planet. Well, strictly speaking, the "Empire" has recently fallen, to have been replaced with a second Roman Republic, but, for the purposes of the central argument, "Empire" and "Republic" could be used interchangeably. Whether we're talking about a unified Empire or a unified Republic is somewhat beside the point.
What is the point of this argument, however, is the kind of peace that has been brought about by the Empire/Republic, also known as the "Pax Romana." The narrator notes in this story that this is not a true peace, of course. There have been many internal wars throughout the history of the Empire/Republic. Rather, he argues that it has brought a relative peace to the planet. That the unification created by the Empire/Republic has minimized the potential for strife.
Given the pluralistic, post-colonial society we live in today, I'd say this isn't exactly a popular point of view when it comes to global politics. However, when you think about it, one could argue that, if the planet was unified under one government, World War I would have never happened. On the other hand, it could also be argued that World War II occurred largely as the result of Imperial impulses, so there you go. Either way you look at it, the story does bring up an interesting point, and one that might just be worth thinking about.