This story takes us to the banks of the Rio Grande river in South Texas. It’s where a cat-and-mouse game plays out every night between migrants crossing into the US illegally and the Border Patrol. That game is intensifying.
The US government has devoted a lot of resources to sealing the US-Mexican border. How effective has the build-up been, and what is the best way to measure it? Marco Werman speaks with Edward Alden, a senior fellow at the Council on Foreign Relations.