We will exceed China's population if you liberals have your way with uncontrolled immigration.  And it is a sociological reality that homogenous societies like Japan are much more stable than heterogenous societies like ours. The Japanese have the benefit of having only ONE indigenous ethnic minority (the Ainu) plus a couple of social castes (the Eta and one other whose names escapes me) who are at the bottom of the social scale, and unjustly oppressed and despised.  Take my post however you wish. Diversity creates disharmony, social conflict, oppression, and disunion.  Where present, it must be managed. But wise societies try to not import more of it.