Hackers often harness the combined power of thousands of virus-infected personal computers to pump out spam e-mail or disable targeted servers by overwhelming them with Internet traffic.

Now an Air Force colonel is suggesting the U.S. military build its own “botnet,” or network of remotely controlled computers, to be ready to attack the computer networks of foreign enemies.

The proposal Col. Charles Williamson III outlined in the May edition of the Armed Forces Journal highlights the creative cyberwarfare strategies being hashed out by the military as hackers abroad step up their attacks on U.S. government computer networks and others around the world.

“The days of the fortress are gone, even in cyberspace,” wrote Williamson, staff judge advocate for Air Force Intelligence in the Surveillance and Reconnaissance Agency at Lackland Air Force Base in Texas. “While America must harden itself in cyberspace, we cannot afford to let adversaries maneuver in that domain uncontested.”