What about Russians, do you consider them asian? The thing is, short of ridiculously complicated, formalized definitions of all races, sub-races, and combinations you're going to have weirdness and misunderstandings. To most people, asian means China/Japan, and/or the accompanying facial-features that are predominant in those areas.

Are all people from Africa black? No, of course not. Are all people from America/Europe white? No, of course not.

So then, why do you want to define the "race" Asian using geography? When all others are based on skin-color/culture/identiy, for lack of a better way of simply-defining it.

At this point, I'm half-expecting someone to correct me about my definition/description of races. Or perhaps be told about some sort of already-formalized, government-endorsed definition of one of the races above that I got wrong.