How can the U.S. increase security along the southern border without building a wall? Stephen R. Kelly says more cooperation between law enforcement agencies on both sides of the border is key. Kelly focused on border issues during his time as Deputy Chief of Mission at the U.S. Mission to Mexico, one of the largest U.S. diplomatic establishments in the world. He served in a similar capacity in Canada. He says many of the tactics now in place in Canada could be implemented on the U.S./Mexico border.