But why did you choose this time around to write about not just “the border,” but about borders in general? My first book was called Border Patrol Nation, so I was looking at the post-9/11 expansion of the border apparatus. And then I looked at also the internationalization of the U.S. border in the third book, called Empire of Borders. Miller: You can look at the U.S.-Mexico border, and then you can look at the border systems around the world, and there’s 70 border walls in various countries. And just looking at the budget then [in ’94], which was $1.5 billion for border and immigration, 4,000 Border Patrol agents.