In the dead of night, from a trailer humming with surveillance monitors, a pilot for the U.S. Customs and Border Protection agency was remotely flying a Predator drone more than 1,000 miles away.

From an altitude of 15,000 feet, over the desert ranchlands of Arizona, the drone’s all-seeing eyeball swiveled and powerful night-vision infrared cameras zeroed in on a pickup truck rattling along a washboard road.