We tend to think of espionage in the United States as an East Coast phenomenon: shadowy foreign spies working out of embassies in Washington, or at missions to the United Nations in New York; dead drops in suburban Virginia woodlands, and surreptitious meetings on park benches in Manhattan's gray dusk.
But foreign spies have been showing up uninvited to San Francisco and Silicon Valley for a very long time. According to former U.S. intelligence officials, that's true today more than ever. In fact, they warn—especially because of increasing Russian and Chinese aggressiveness, and the local concentration of world-leading science and technology firms—there's a full-on epidemic of espionage on the West Coast right now. And even more worrisome, many of its targets are unprepared to deal with the growing threat.