Command’s top official, Gen. Keith Alexander, suggest that the military’s cyberwarriors are up against bigger challenges than having to prove that they are not spying on U.S. citizens. Cybercom, 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.

The biggest hurdle for Cybercom is that it lacks comprehensive visibility of the entire  US 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 situational awareness in our networks so if we see something we can take action in real time,” said Alexander.

Defense contractors often advertise software products that provide such awareness, but these magic solutions don’t yet exist, said Alexander. “We do not have a common operating picture for our networks,” he said. “We need to build that.”

Companies say they are working on it, “but we don’t have it, not in the breadth that we need,” said Alexander. In maneuver warfare, military commanders on the battlefield need situational awareness so they can pinpoint the location of the enemy and try to anticipate what it might do. In cyberspace, there is no such capability, said Alexander. “Oftentimes our situational awareness is just forensics. Something has happened and we’re responding.”

Plugging this gap will require not just new technology but also extensive coordination among the military services and other federal agencies, he said. Alexander, who serves as Director of the National Security Agency and head of U.S. Cyber Command, spoke to a standing-room-only crowd this morning at the Center for Strategic and International Studies. He acknowledged that his dual-hatted job running the secretive intelligence-gathering NSA and Cybercom raises legitimate concerns about the government’s potential violation of citizens’ privacy rights.

Defense Department systems are probed by unauthorised users 250,000 times an hour, said Alexander. But most of these intrusions are of rather mundane nature — the result of poorly engineered software, missing patches and poor configuration, he said.

What Cybercom leaders fear the most is a strike on military networks that would compromise U.S. forces’ command-and-control systems, and therefore undermine an entire campaign. The military depends on information network for just about every aspect of its operations. Any attack would be difficult to prevent and the perpetrators may not be easy to identify, said Alexander.

These concerns point to a larger dilemma for the Defense Department: how to cope with the neck-breaking growth of the Internet, which just keeps breeding millions of potential hackers. The military is hooked on the Internet just like everyone else, and despite the sophisticated firewalls that the Pentagon has built around its computer systems,

Alexander, worries about a future that is only going to be more populated by users and exploiters of the Internet. In 1996, there were 16 million Internet users worldwide, he said. Today, there are 1.8 billion. Even more worrisome for the Pentagon is that its potential battlefield for cyber warfare is so vast and global — 47 percent of email users are in Asia, 23 percent in Europe, and just 14 percent in North America, with 16 percent elsewhere.

Making matters more complex for Cybercom is that its goals in some way clash with the Pentagon’s stated pursuits of information sharing. “Information security in the 21st century has to look different, because it has to not just be the kind of mentality where you kind of wall yourself away, but a way to raise the bar in security that allows you to share at the same time,” said David M. Wennergren, deputy assistant secretary of defense for information management and technology, and deputy chief information officer for the Department of  Defense. “These two things have to be front and center on our plate.”