More specifically - is there a term or a tradition of thought which has a concept or a conception of the "West" which incorporates Islam and the territory more or less until the borders of the Oxus, a la Alexander.

It seems to me that in many areas (cosmological, theological, to some extent technological...) the Indo-European "Alphabetical" cultural zone has for long periods of history represented a unified space of exchange, relative to which the zone defined by Asian scripts like Chinese Hanzi, and Asian religious traditions represent the real Other, so to speak, and I'd be curious to know whether anyone serious has developed or conceptualized this thought.