Book excerpt: Richard A. Clarke warned America once before about the havoc terrorism would wreak on our national security—and he was right. Now he warns us of another threat, silent but equally dangerous. Cyber War is a powerful book about technology, government, and military strategy; about criminals, spies, soldiers, and hackers. It explains clearly and convincingly what cyber war is, how cyber weapons work, and how vulnerable we are as a nation and as individuals to the vast and looming web of cyber criminals. This is the first book about the war of the future—cyber war—and a convincing argument that we may already be in peril of losing it.