The Age of Walls, 3: How Barriers Between Nations Are Changing Our WorldTim Marshall, the New York Times bestselling author of Prisoners of Geography, offers "a readable primer to many of the biggest problems facing the world" (Daily Express, UK) by examining the borders, walls, and boundaries that divide countries and their populations. The globe has always been a world of walls, from the Great Wall of China to Hadrian's Wall to the Berlin Wall. But a new age of isolationism and economic nationalism is upon us, visible