Washington Post 
Nov 15, 2012
President Obama has signed a secret directive that effectively enables the military to act more aggressively to thwart cyberattacks on the nation’s web of government and private computer networks.
Presidential Policy Directive 20 establishes a broad and strict set of standards to guide the operations of federal agencies in confronting threats in cyberspace, according to several U.S. officials who have seen the classified document and are not authorized to speak on the record. The president signed it in mid-October.
The new directive is the most extensive White House effort to date to wrestle with what constitutes an “offensive” and a “defensive” action in the rapidly evolving world of cyberwar and cyberterrorism, where an attack can be launched in milliseconds by unknown assailants utilizing a circuitous route. For the first time, the directive explicitly makes a distinction between network defense and cyber-operations to guide officials charged with making often-rapid decisions when confronted with threats.
The policy also lays out a process to vet any operations outside government and defense networks and ensure that U.S. citizens’ and foreign allies’ data and privacy are protected and international laws of war are followed.