More than three years ago, the CIA dispatched a stealth surveillance drone into the skies over Iran.

The bat-winged aircraft penetrated more than 600 miles inside the country, captured images of Iran’s secret nuclear facility at Qom and then flew home. ...

CIA stealth drones scoured dozens of sites throughout Iran, making hundreds of passes over suspicious facilities, before a version of the RQ-170 crashed inside Iran’s borders in December. ...