El Paso, Texas was the safest city in the U.S. in 2010.

Juarez, Mexico, across the Rio Grande river, had the highest murder rate in the world in 2010.

This incredible division emerged thanks to a confluence of global forces, according to Michael Casey's new book, "The Unfair Trade." These include the rise of Chinese manufacturing and subsequent decline of Mexican manufacturing; the rise of violent drug cartels to fill the void; and U.S. drug and immigration policies that have set Mexico on fire.

Casey describes the juxtaposition:

The economic outlook for small-business owners in [Juarez] is gloomy. According to the Juárez Restaurants Association, half of all dining establishments closed in the three years leading up to 2011, many shifting operations to El Paso. In a bitter irony, the neighboring Texas city boasts the lowest crime rate in the United States, a natural marketing advantage with which the newly relocated restaurants appeal to those Juárez residents who are free to travel to the United States and prepared to put up with a long wait at the border. Not so long ago, the flow went the other way. The Mexican city, where the margarita cocktail was invented in 1942, was an entertainment mecca, home to countless restaurants, nightclubs, casinos, bars, and hotels. In the mid-2000s, American teenagers would still wander across the International Bridge spanning the Rio Grande to visit watering holes on the Juárez side, where the drinking age was lower and where the scene was far more lively than in El Paso. But the bars on the street next to the bridge have all since closed, replaced by businesses catering to northbound travelers such as moneychangers and travel accessory stores. Meanwhile, those restaurants that still operate in other parts of Juárez now typically serve breakfast and lunch but rarely do dinner, because at night patrons are scared of being the target of a kidnapping or hit with a barrage of bullets.

Casey's book describes how the global financial system dominated by China and the U.S. is also causing trouble in Australia and Indonesia and among the U.S. middle class.