There is much to fear in the dark corners of cyberspace. From well-covered stories like the Stuxnet attack which helped slow Iran’s nuclear program, to lesser-known tales like EternalBlue, the 2017 cyber battle that closed hospitals in Britain and froze shipping crates in Germany in midair, we have entered an age in which online threats carry real-world consequences. But we do not have to let autocrats and criminals run amok in the digital realm. We now know a great deal about how to make cyberspace far less dangerous–and about how to defend our security, economy, democracy, and privacy from cyber attack.

This is a book about the realm in which nobody should ever want to fight a war: the fifth domain, the Pentagon’s term for cyberspace. Our guides are two of America’s top cybersecurity experts, seasoned practitioners who are as familiar with the White House Situation Room as they are with Fortune 500 boardrooms. Richard A. Clarke and Robert K. Knake offer a vivid, engrossing tour of the often unfamiliar terrain of cyberspace, introducing us to the scientists, executives, and public servants who have learned through hard experience how government agencies and private firms can fend off cyber threats.