Jack of Harts

The Japanese culture of the Twentieth Century was heavily rooted in the idea that the Japanese race was superior to all others.  Even other Asians were less human than the Japanese, and so they knew without doubt that the world would bow to them in time.  This bone-deep belief was bolstered as they watched the Europeans make the insane decision to release their hard-won conquests throughout the world.  Japan saw that as a sign of weakness and chose to act on it.