A powerful element of xenophobic racist ultra nationalistic egomania has contributed to this lack of integration.

The Japanese have turned in upon themselves like stunted chrysanthemum blossoms.

Besides the nuke problem, the Japanese's chief worry will be their declining birth rate/exploding elderly population timebomb. If they had allowed more integration and weren't so anal about things, they wouldn't now be worried about using robots to wipe old folks' asses. Although, if I had to choose, I'd prefer to send a robot to do it for dear old grandpa. If I still had one.