Cyber command: we cannot prevent attacks.

• Author: Erwin, Sandra I.
• Position: DEFENSEINSIDER

* U.S. Cyber Command, whose main mission is to protect military information networks from hackers and foreign spies, has the world's most advanced technology, but still faces huge obstacles in its ability to shield U.S. networks from malicious attacks, said its commander, Army Gen. Keith Alexander.

The biggest hurdle for Cybercom is that it lacks comprehensive visibility of the entire Defense Department's digital domain, which limits its capacity to prevent attacks, Alexander said. Cybercom only becomes aware of intrusions after they happen, and then reacts to the events, because it has little "situational awareness" of what is going on across Defense Department networks before cyberattacks occur.

"We are policing after the fact, versus mitigating in real time," he said. "We need real time...