A secret legal review on the use of America's growing arsenal of cyberweapons has concluded that President Obama has the broad power to order a pre-emptive strike if the United States detects credible evidence of a major digital attack looming from abroad, according to officials involved in the review.
That decision is among several reached in recent months as the administration moves, in the next few weeks, to approve the nation's first rules for how the military can defend, or retaliate, against a major cyberattack. New policies will also govern how the intelligence agencies can carry out searches of faraway computer networks for signs of potential attacks on the United States and, if the president approves, attack adversaries by injecting them with destructive code - even if there is no declared war.
The rules will be highly classified, just as those governing drone strikes have been closely held. John O. Brennan, Mr. Obama's chief counterterrorism adviser and his nominee to run the Central Intelligence Agency, played a central role in developing the administration's policies regarding both drones and cyberwarfare, the two newest and most politically sensitive weapons in the American arsenal.