A decade ago, Martin Libicki wrote Defending Cyberspace, and Other Metaphors. Among other things, two essays examine the utility of the metaphor of "cyberspace" in military thinking:
"Deterring Information Attacks," continues the examination of the metaphor that information warfare is indeed warfare by discussing the problems of retaliation and asking whether an explicit policy of retaliation is workable and thus likely to deter….
The last essay, "Point, Counterpoint, and Counter-counterpoint," was inspired by a search for a new metaphor for new kinds of warfare. Conflict has classically been modeled by orthogonal lines of defense and attack. Today's asymmetric warfare is about points, blots, and gated fences, topological forms with particular applicability to information warfare.
Tonight I see that Libicki's latest book, Conquest in Cyberspace: National Security and Information Warfare, is coming out this year. From the Cambridge Press catalog description:
With billions of computers in existence, cyberspace, 'the virtual world created when they are connected,' is said to be the new medium of power. Computer hackers operating from anywhere can enter cyberspace and take control of other people's computers, stealing their information, corrupting their workings, and shutting them down. Modern societies and militaries, both pervaded by computers, are supposedly at risk. As Conquest in Cyberspace explains, however, information systems and information itself are too easily conflated, and persistent mastery over the former is difficult to achieve.