A chilling and revelatory appraisal of the new faces of espionage and warfare on the digital battleground Shortly after 9/11, Joel Brenner entered the inner sanctum of American espionage, first as the inspector general of the National Security Agency, then as the head of counterintelligence for the director of National Intelligence. He saw at close range the battleground on which adversaries are attacking us: cyberspace. Like the rest of us, governments...