The DOD has stated that Cyberwar is real. Our US networks have been attacked by China. I heard on CNN that our Secretary of Defense's computer was also penetrated. I do not know if this is true. President Bush says it's not.
The Air force has some of the best cyberwarriors. They have classes to train our troops on information warfare. The have a degree in Cyberwarfare. It's in the electrical and engineering department. They train on IP networks, telecommunications, radars, satellites, transportation systems, and power systems.
The NSA also does try to stop these attacks. The DOD had one of the lowest security rating's out of goverment agencies. The National Science foundation had some of the best security.