For the first time, the Pentagon has decided that cyber attacks constitute an act of war, reports The Wall Street Journal. The U.S. military drafted a classified 30-page document concluding that the U.S. may respond to cyber attacks from foreign countries with traditional military force, citing the growing threat of hackers on U.S. infrastructure such as subways, electrical grids or nuclear reactors. "If you shut down our power grid, maybe we will put a missile down one of your smokestacks," a military official told the Journal. While some say the policy is in keeping with the times, others worry that it could lead the country into war more easily. 

"The next time someone wants to invent a casus belli against Iran, they can just point to a particularly successful hack," writes liberal bloger Marcy Wheeler. She envisions a hypothetical where the U.S. makes the case for war against Iran after a cyber attack, "ignoring all questions about appropriate retaliation for Stuxnet" (an anti-Iran computer virus rumored to have been created by Israel in cooperation with the U.S.).

But Stephen Shankland at CNET says the policy change is a long time coming. "The views shouldn't be a shock to anyone. Long gone are the days when computer networks weren't an essential part of the military, the economy, and the infrastructure of first-world countries," he writes. "Cyberattacks may not be as obvious as exploding bombs, and defenses may not be as obvious as machine gun nests. But particularly in military circles, where people are accustomed to seeing the world in offensive and defensive terms, cyberwar can hardly be seen as anything but a newer facet of regular war."

Almost everyone acknowledges, however, that the trick with cyber attacks is determining where the attacks come from. According to the Journal, the Pentagon "left unaddressed... whether the U.S. can ever be certain about an attack's origin, and how to define when computer sabotage is serious enough to constitute an act of war." The paper says these topic continue to be in "dispute within the military." 

"One idea gaining momentum at the Pentagon is the notion of 'equivalence,' reports the Journal. "If a cyber attack produces the death, damage, destruction or high-level disruption that a traditional military attack would cause, then it would be a candidate for a 'use of force' consideration, which could merit retaliation."

A worrying parallel Wheeler raises is the George. W. Bush administration's weapons of mass destruction argument with the Iraq War. "[The government could] claim the Iranians have done it and say it, like evidence of WMD, is classified." The Journal cites the Bush administration's justification for the war in Afghanistan. "A parallel, outside experts say, is the George W. Bush administration's policy of holding foreign governments accountable for harboring terrorist organizations, a policy that led to the U.S. military campaign to oust the Taliban from power in Afghanistan."