U.S. crafting framework for cyber offense: general

Deliberations on military doctrine and legal framework are "ongoing," Air Force General Robert Kehler, commander of the U.S. Strategic Command, told a defense writers' group. "I would say it's not completed."

Kehler has overall responsibility for the U.S. Cyber Command, a sub-unit that began operating in May 2010.

Its mission is to protect Defense Department networks and, if ordered, to go on the offensive to make sure the United States retains the ability to use digitally networked systems on land, at sea and in the air.

He said the military was still looking at "what kinds of options would we want to be able to offer" policymakers for going on the offense.

One of the issues is what constitutes "active defense" in cyberspace, he said, equating it with actions that a ship's captain is authorized to take at sea to protect a ship.

"Is active defense really offense in cyberspace?" Kehler asked. "I would argue that it really is not. It does not have to be, for sure. But those are the issues that we are trying to work our way through."

The Defense Department unveiled in July the broad outlines of a strategy for protecting its more than 15,000 computer networks. The strategy defined cyberspace as an "operational domain" that U.S. forces will be trained to defend, like air, sea and land.

Then-Deputy Defense Secretary William Lynn said the Pentagon wanted to avoid militarizing cyberspace, but aimed to secure strategic networks with the threat of retaliation, as well as by mounting a more robust defense.

"Our strategy's overriding emphasis is on denying the benefit of an attack," Lynn said in a July 14 speech at the National Defense University. "If an attack will not have its intended effect, those who wish us harm will have less reason to target us through cyberspace in the first place."

The U.S. Defense Department has said that it expects cyberattacks to be a "significant component" of future conflicts. More than 30 countries are creating cyber units in their militaries, Lynn wrote in a September 28 piece on ForeignAffairs.com just before stepping down this month.

Cyber technologies now exist that are capable of destroying critical networks, causing physical damage by playing havoc with industrial control systems and altering key systems' performance.

Kehler in his remarks Tuesday said cyberspace is a place "through which we'll conduct military activity, similar to every other domain."

Asked how U.S. cyber capabilities measured against potential adversaries such as Russia and China, he said: "I believe the that the United States still has an edge."

"I can't describe how great the edge is," Kehler said. "I can tell you in some places I think we have quite an edge in cyberspace." He declined to elaborate.

Kehler suggested debate may be continuing on whether electronic warfare -- in which the electromagnetic spectrum is used against targets such as radio towers, radars and other services -- could be construed as a form of cyber warfare.

"I think you could say no," he said. "We've done electronic warfare for years and years and years and years."

(Editing by Cynthia Osterman)