President Barack Obama has called on national security leaders to develop destructive cyberwarfare capabilities that could be triggered with "little or no warning" against adversaries around the world, according to a top-secret document obtained by The Washington Post.

Presidential Policy Directive 20, issued to national security and intelligence officials in October, includes an array of procedures to ensure that cyber-attacks are lawful and minimize damage. But the directive indicates the government believes that cyber-attacks — known as "offensive cyber effects operations" (OCEO) — are becoming common and that cyberwar could be just around the corner.

"OCEO can offer unique and unconventional capabilities to advance U.S. national objectives around the world with little or no warning to the adversary or target and with potential effects ranging from subtle to severely damaging," the document said. "The United States government shall identify potential targets of national importance where OCEO can offer favorable balance of effectiveness and risk as compared with other instruments of national power."