The temporary closure of airspace over El Paso, Texas has caused unease south of the U.S. border and put the spotlight on the use of drones by Mexican cartels.

U.S. officials warn that cartel-operated drones on the border pose a major threat. Mexican officials are less certain. Analysts say the answer is likely in between.

U.S. officials say they have seized thousands of pounds of drugs flown in by drones over the border. Mexican officials have ...