In other words, walls used to generate borders, not the other way around. But according to Graziano, beginning in the 17th century, as capitalism began to take root across Europe, borders became the way of creating and enclosing the nation, and with it, the national market. “The subjects of the same prince had to be able to recognize each other, understand each other, and obey the same distinctive characteristics and the same laws. In short, they had to become—even if the word only appeared much later—a nation,” Graziano writes.
Border regions, as at the boundary between the Mexican state of Coahuila and the American state of Texas— which were once a unified political unit— might share a climate, an ecosystem, and a culture, but once the border was established, they could not share an economy.
Which is not to say that they don’t have economic relationships. As the United States border with Mexico shows, there is a lot of money to be made at the boundary between two different national economies. The border acts as a membrane that keeps labor on one side cheap, while consumers on the other retain the high-incomes to buy incoming goods. Make a fridge in Tijuana, paying wages in pesos, truck it across the border to San Diego and sell it for dollars—and you can make a lot of money. (Hence, the decades of the maquiladora system.) The same holds true for Chinese manufacturing and the ports of the West Coast, it’s just that the border zone is the largest body of water on Earth and it takes six weeks to cross in a boat longer than the Empire State Building is tall.
In Western countries, especially since 9/11, this market membrane has run smack into a competing desire to keep out some people, however that group of, as the Border Patrol puts it, “inadmissables,” is defined.
In 2007, the British government put its policy like this: “The aim of border control is to sort traffic into legitimate and non-legitimate.” As the scholar Nick Vaughan-Williams points out, there are actually two goals in the UK (as in the US) border policy. “Rather than operating simply as a ‘barrier’ or obstacle in the physical sense of a wall, ‘the border at work’ here is one that seeks to enhance mobility, circulation, and flow,” Vaughan-Williams wrote.
To accomplish these two seemingly at-odds goals, the American answer has been to create a more sophisticated, technologized border, one that uses data to allow some people and goods to pass extra fast while slowing or repelling others. The more the border is hardened, the more urgent and complex the programs that allow some valuable people and goods to pass freely become. Hence, the War on Terror’s airport crackdown and watch lists also spawned the Global Entry program for frequent—and “trusted”—international travelers. A tightening southern border led to Free and Secure Trade, a special trucking program to for “trusted” shippers, which want to get as close to the ideal of frictionless border crossing as possible.