What makes sense?

I'm reading Tropic of Night, an entertaining supernatural thriller by Michael Gruber. The story concerns African sorcery, as performed by an imaginary tribe called the Olo. An Olo sorcerer who carries out a particularly grizzly series of human sacrifices called okunikua acquires extraordinary power:

No Olo has done okunikua since some time before the turn of the last century. . . . The Olo witch who did it, whose name the Olo never mention, was annoyed by French civilization and wished to make it go away, which in time, of course, it did. The Olo patriarchs considered that the two World Wars, the Great Depression, and the consequent reduction of the great colonial powers to little postcard nations were a direct result of this guy's okunikua. They approved of the result but, as moral people, thought the means excessive. Western historiography does not agree, since it is much more logical to assume that millions of fairly rational, marvelously educated, prosperous people went crazy and ripped the heart out of their own civilization.