Viva la Schneier!

A very good article on the what a Cyber War entails. Taken from here

Using cyber attacks to spy on another nation is a grey area, which gets greyer still when a country penetrates information networks, just to see if it can do so. Penetrating such networks and leaving a back door open, or even leaving logic bombs behind to be used later, is a harder case—yet the US and China are doing this to each other right now.