If I could, I would repeal the Internet. It is the technological marvel of the age, but it is not — as most people imagine — a symbol of progress. Just the opposite. We would be better off without it. I grant its astonishing capabilities: the instant access to vast amounts of information, the pleasures of YouTube and iTunes, the convenience of GPS and much more. But the Internet's benefits are relatively modest compared with past transforming technologies, and it brings with it a terrifying danger: cyberwar. Amid the controversy over leaks from the National Security Agency, this looms as an even bigger downside.

By cyberwarfare, I mean the capacity of groups — whether nations or not — to attack, disrupt and possibly destroy the institutions and networks that underpin everyday life. These would be power grids, pipelines, communication and financial systems, business record-keeping and supply-chain operations, railroads and airlines, databases of all types (from hospitals to government agencies). The list runs on. So much depends on the Internet that its vulnerability to sabotage invites doomsday visions of the breakdown of order and trust.

In a report, the Defense Science Board, an advisory group to the Pentagon, acknowledged "staggering losses" of information involving weapons design and combat methods to hackers (not identified, but probably Chinese). Hackers might disarm military units. "U.S. guns, missiles and bombs may not fire, or may be directed against our own troops," the report said. It also painted a specter of social chaos from a full-scale cyberassault. There would be "no electricity, money, communications, TV, radio or fuel (electrically pumped). In a short time, food and medicine distribution systems would be ineffective."