The morality of a cyberwar can be discussed until all participating parties are blue in the face. However, the reality of the issue is that it's not a matter of morality, but a matter of time; whether it's an all-out cyberwar between two or more countries, or whether it's private groups waging cyber guerrilla warfare against a perceived evil, there will be cyber battles in our future.
I speak of the event of cyberwarfare with such certainly simply because, from a logistics standpoint, it is the next logical step for warfare. The question of it's morality, while interesting from an educational standpoint, is irrelevant from a realistic standpoint. Cyberwarfare is more accessible, cheaper, and more efficient than classic warfare. Military equipment is expensive and extremely difficult to obtain in relation to computers. Also, computers level the playing field in many ways. Not many factions that oppose the United States are going to be able to afford to build stealth bombers costing over a billion dollars. However, with a computer, an internet connection, and the proper knowledge, one person could potentially do much more towards damaging the United States than the same person with an AK-47 could.
Denial of service attacks (as talked about in "The Rights and Wrongs of Hacktivism" http://www.economist.com/node/17732839?story_id=17732839) are relatively simple and can be executed by almost anybody, particularly once the code is written. The simplicity of these attacks, however, hides how effective they can be against an unprepared opponent. Giant corporations such as Amazon and Master Card were brought to their knees (temporarily) by 10,000 hacktivists. What could 100,000 hacktivists, or worse yet 100,000 well trained cyber warriors accomplish?
The PC is a powerful weapon. It is only a matter of time before it "falls into the wrong hands". When this time comes, the United States needs to be prepared, both defensively and offensively.