Firstly, the title is a somewhat misleading. This book describes the cultural and political divides for a number of countries. These divides are regional within each country; creating internal to the country borders. But, I wouldn't call the divides "great" or "mankind's great". Nevertheless, I consider this book very well worth reading for the general-interest reader. This is a non-fiction book, so don't expect a lot of page-turning drama. The author has done a very good job of providing first-hand interviews with the people residing at the borders of the divides highlighted. What I found especially interesting was the last chapter on the Soviet Union, Russia, Stalin and Vladimir Putin. This chapter had nothing to do with divided regions within a country's people, but I was fascinated by what the author had to say about the accomplishments of Mr. Putin.