It will probably take something akin to the catastrophe Clarke imagines in his book.
UNDEFENDED: Like much of the infrastructure we depend on, America’s power grid is vulnerable to malicious hackers.
But if we're so vulnerable, why haven't we suffered a catastrophic attack already?
Ryan Singel of wired.com, a leading skeptic, has labeled all the talk of digital cataclysm "Cybarmageddon!" Dark warnings of logic bombs in the power grid are unfounded, he argues, and "the Chinese can't blunt the power of 15 carrier groups with some fancypants, unheard-of ninja cyber-coding tricks."
Lin, of the National Research Council, offers no opinion on whether the cyber threat is overblown. But he says it is particularly susceptible to worst-case scenario gaming.
"In the Cold War, we were worried about the Soviet nuclear capability, but we had satellites that could count how many missiles they had," he says. "There's no equivalent to that now. There's no counterweight to the people who say, 'Well, this might happen or that might happen or the other thing might happen.' "
The most cynical reading has figures like McConnell, who has suggested that a coordinated cyber attack could be as devastating as a nuclear bomb, ginning up the threat to drive business: he is, after all, an executive vice-president with defense contractor Booz Allen Hamilton these days.
Goldsmith, the Harvard law professor, has a more charitable view of the doomsayers. But in a review of Cyber War, he points to another flaw in the we're-on-the-brink view: Clarke fails to provide a convincing argument as to why China would launch a major cyber attack on the United States, given its deep dependence on the American economy.
Indeed, with hackers pilfering terabytes of intellectual property from American business, it's hard to imagine why they would disable the conduit to China's next great leap forward.
James Lewis, a former State Department official now with the Washington-based Center for Strategic & International Studies, says we shouldn't rest easy, though. "The Russians and the Chinese — they're not just going to launch a war for the fun of it," he says. "But I'm not sure I'd say that for everybody on the planet."
Rogue states like North Korea and Iran are of concern, of course. But the biggest worry is terrorist groups like Al Qaeda, unchecked by the political or economic considerations that weigh on Moscow, Beijing — and even Tehran.
"They don't have the capability now or they would have used it," says Lewis, who led work on a major cyber-security report for the Obama administration as it was preparing to take office. "It's not really comforting, though, because this kind of attack capability has probably been around for . . . four or five years. And what we know is the high-end technologies eventually flow into the commodity space."
Lewis says he was privy in the mid '90s to highly classified technology in the possession of the National Security Agency — the world's premier digital snoop — that is now widely available on the Internet.
It won't be long, he says, before Al Qaeda or Hezbollah gets its hands on the latest tools in cyber warfare: "Within a decade, we're going to face this threat."