What is the theme in King Leopold's Ghost by Adam Hochschild?

The basic theme of the text is the process of colonialism, the extension of one nation's sovereignty over a territory beyond its borders. The specific instance of colonialism most-closely examined in the text is Leopold's establishment of an administrative dependency in the Congo, causing its native peoples to be directly ruled by a distant and absentee administration. Leopold's structure was a system of direct political and economic intervention in the Congo, which was made possible without significant military force by the fragmented nature of the traditional tribal structures in place at the time of Leopold's colonization.