WU and ZU, the two warning underground nations in Stanton Coblentz's novel In Caverns Below. You have two societies populated by people who give no thoughts about anything including their lot lot in life. They allow themselves to be ruled leaders who are autocratic and incompetent and dangerously inbred because for generations, they have allowed no marriages outside their class. These leaders have not the slightest concern for the welfare of those whom they rule over not the harm they cause to them . The problem is the people are so patriotic and unthinking that , they think that there is nothing wrong with any of this. The reasons for the war between the two nations ? None that makes any sense.