The head of the National Security Agency, Army Gen. Paul Nakasone, has a catchphrase: "persistent engagement."
This covers a broad spectrum of cyber activities at the nation's largest spy agency. But at its core, it means relentlessly tracking adversaries, and increasingly, taking offensive action against them.
"That's the idea of persistent engagement. This idea of enabling and acting," Nakasone recently told NPR. When he took over the agency last year, he said that rivals didn't fear the U.S. in the cyber realm, and he intended to change that.