From the air, the terrain of the Department of Energy’s Nevada National Security Site, with its arid high plains and remote mountain peaks, has the look of northwest Iran. The site, some sixty-five miles northwest of Las Vegas, was once used for nuclear testing, and now includes a counterintelligence training facility and a private airport capable of handling Boeing 737 aircraft. It’s a restricted area, and inhospitable—in certain sections, the curious are warned that the site’s security personnel are authorized to use deadly force, if necessary, against intruders.