Yet questions remain concerning the construction of global perspectives themselves. One question has to do with ideology: To what extent does world history represent particular political or economic interests? From early times to the present, desire to know the larger world has been most prominent among expansive imperial and commercial powers such as the Roman empire, Han China, the Abbasid caliphate, Tang China, the Mongol empire, the British empire, and the United States. Efforts to know the larger world inevitably mirror some kind of interest in the larger world. In the form of area studies as well as world history, some of those efforts have clearly reflected immediate political and economic interests. It does not follow, however, that global historical analysis is necessarily an ideological tool of imperialism or global capitalism, any more than historical scholarship on Adolf Hitler necessarily valorizes Nazi ideology. Indeed, any critical approach to world history necessarily recognizes that global processes have produced fragmentation as well as integration, misery as well as prosperity.