Four small, white passenger planes sit outside a hangar here under a blazing sun, with no exterior markings save for U.S. registration numbers painted on the tails. A few burly men wearing aviator sunglasses and short haircuts poke silently around the wing flaps and landing gear.

The aircraft are Pilatus PC-12s, turboprops favored by the U.S. Special Operations forces for stealth missions precisely because of their nondescript appearance. There is no hint that they are carrying high-tech sensors and cameras that can film man-size targets from 10 miles away.