I don't know about the world, but in the United States race is constructed only partly according to pigmentation and area of ancestral origin. A number of ethnic groups have started out as non-White, moved to not-quite-White, and finally became White, the Irish, Italians, and Jews, for example. East Asians in the U.S. are presently moving from the not-quite-White to the White category. One evidence of this was the way in which mainstream newscasters, during the disturbances in Los Angeles, construed Korean shopkeepers as White and Mexicans as non-White.
So Japan as a nation could be reconstrued as effectively White, and even find allies among White people -- the Germans, for example -- without really affecting the basic structure of Whiteness.
Gordon