Could you elaborate? What do you mean by the devaluing of human life in the East?

The dichotomy between an individualistic west and a collectivist east is overstated: even a Confucius or Buddha and their followers took care to leave us their name, unlike many later westerners whose works are renowned. The medieval west too was founded on concepts of social order and cohesion, each in his place, most obligated by inherited status: the rise of today's individual seems associated with later cultural shifts associated with material development and increased expectations of life - its quality, variety and duration.

I wouldn't set much store by the more lurid accounts of rampaging hordes butchering tens of millions: in the absence of reliable "before" and "after" numbers there's really little evidence beyond chroniclers' wild reports. That great bloodshed occurred seems clear, that it affected enough of the region's people to make a lasting fundamental impact on notions of life and personhood a good deal less so.