An electronic attack forced the Department of Defense to take between 1,000 and 1,500 Pentagon computers offline last Wednesday. The intrusion affected the department’s unclassified electronic mail system, which transmits messages regarding administrative business. Defense officials detected no penetration of systems containing classified messages on military operations.

On the same day, a congressional panel reported that electronic systems at the Department of Homeland Security had also been hacked.

“What does this mean? It means terrorists or nation states could be hacking Department of Homeland Security databases, changing or altering names to allow them access to this country, and we wouldn’t even know they were doing it,” Congressman James Langevin said.

Defense Secretary Robert Gates said the Pentagon comes under hundreds of electronic attacks each day but declined to say why the Wednesday penetration necessitated disconnecting such a large number of computers.

U.S. military dependence on network technology has increased in recent years, while arguably its network security has not. As it has integrated more and more elements into its electronic systems, the Pentagon has turned increasingly to commercially developed software, which is more advanced but less secure than programs the military could produce in-house.

The military depends not only on commercial software systems from providers such as Cisco, but also necessarily ties many of its systems to civilian networks. In the U.S., 95 percent of military transmissions are communicated using secure connections to civilian networks. In recent years, supercomputer laboratories, nasa systems, research centers, software security developers including Cisco, and other networks have been hacked, many from locations inside Europe and China.

Trumpet editor in chief Gerald Flurry has highlighted network dependence as one of the United States’ largest weaknesses for several years. “One of the main reasons we won World War ii was because the British broke German radio code,” he wrote in June 1999. “We could lose the next war before we even begin, if somebody breaks our military codes.”

For analysis on U.S. technology dependence and the consequences if America gets logged off, read “America’s Achilles Heel—and Germany” and “The Penetrable Fortress.”