The U.S. Department of Defense has announced a set of five guiding strategic principles for better preparing its forces to handle operations to defend the nation in cyberspace.The strategy's central tenet is that the United States' posture in cyberspace must mirror its approach to other domains: Land, sea, air and space. The Pentagon aims to prepare its forces to respond to attacks by other nations as well as rogue groups, while avoiding the militarization of cyberspace and preserving citizens basic freedoms, William Lynn, III, Deputy Secretary of Defense, said in prepared remarks."Just as our military organizes to defend against hostile acts from land, air and sea, we must also be prepared to respond to hostile acts in cyberspace," Lynn said. "Accordingly, the United States reserves the right, under the laws of armed conflict, to respond to serious cyber attacks with a proportional and justified military response at the time and place of our choosing."Also see: An EARLY government cybersecurity timelineAs outlined in the strategy, the Pentagon will treat cyberspace as an operation domain, similar to land, air, sea and space. In addition, the military will deploy more active defenses, mine civilian expertise to help it in its mission, and work with allies to track cyberspace threats that impact all nations. Finally, the Pentagon plans to push for more research, technological expertise and training within the United States to raise our capability to defend against cyberattacks.Much of the strategy has previously been talked about by military officials and experts. On Tuesday, for example, the White House announced that the U.S. and Russia had reached an agreement to regularly exchange information on technical threats, to clarify each other's military views, and to establish a hotline to discuss ongoing attacks during crises."Both the U.S. and Russia are committed to tackling common cybersecurity threats while at the same time reducing the chances a misunderstood incident could negatively affect our relationship," Howard Schmidt, the White House cybersecurity coordinator, wrote in a blog post.Also see: White House pushes online trusted IDsWhile U.S. military power will likely deter other nation-states from overt attacks on U.S. networks, rogue groups, hacktivists and cybercriminals have less to lose, and the Pentagon assumes that they will attack when they can."If a terrorist group gains disruptive or destructive cyber tools, we have to assume they will strike with little hesitation," Lynn says. "And it is clear that terrorists groups, as well as rogue states, are intent on acquiring, refining, and expanding their cyber capabilities."Among the strategy's announcement, the commitment to work with private industry is the most exciting, says Jason Clark, chief security officer for content security firm Websense. In the past, the government has always asked for information from private industry, but the act was less of an exchange and more of a sinkhole. Sharing information with industry could help the companies in charge of critical infrastructure to better defend themselves, he says."Today, we just share information upstream, and we don't get much downstream," Clark says. "So it certainly has to change were it is a lot more of a shared intelligence community."