Russia is suspected of having used computer attacks during its war with Georgia in 2008.
While computer security experts say China is most active and persistent, it is not alone in using computer attacks for a variety of national purposes, including corporate espionage.
According to anonymous senior administration sources, quoted in the New York Times, President Barack Obama decided to speed up an initiative launched by his predecessor, George W Bush, codenamed Olympic Games, which aimed to use computer viruses to attack Tehran's uranium-enrichment programme.
The stunning revelations by Mr. Sanger, The New York Times's chief Washington correspondent, about the American role in using computer warfare to attack Iran's nuclear program already have made headlines, and rightly so.
These attacks used computers at multiple locations to overwhelm the vendors' computers and shut down their World Wide Web (WWW) sites to legitimate commercial traffic.
But DARPA is building a real version that's designed to make both cyberdefense and attacks using computer technologies more immersive, giving military hackers a way to look around the data and go "swimming in the Internet," as DARPA Plan X program manager Frank Pound explained to WIRED.
The secretive new office, headed by an Air Force general, Simon Worden, envisions using a mix of truthful news releases, phony stories and e-mails from disguised addresses to encourage the kind of news coverage abroad that the Pentagon considers advantageous, while using clandestine activities, including computer network attacks, to disrupt coverage it opposes.
For years military experts and computer scientists have speculated about the possibility of a nation's infrastructure being attacked using computers, rather than bombs.
Learn how to use computers.
Or a hacker may want to hijack your computer to use it to attack web sites or to store illicit material on it, such as pornography or stolen intellectual property.
