Testifying as President Clinton left for a state visit aimed at strengthening ties with Beijing, Tenet said the magnitude of the threat from a wide range of potential foes, by implication including China, was "extraordinary."
He cited the danger of various forms of intrusion into networked information systems, tampering and "delivery of malicious code."
"We know with specificity of several nations that are working on developing an information warfare capability," the chief U.S. spymaster told the Governmental Affairs Committee.
Through high-tech attacks, "information warfare" would exploit growing reliance on the bits and bytes that weave modern societies together for everything from telecommunications to power grids and banking.
"It is clear that nations developing these programs recognize the value of attacking a country's computer systems both on the battlefield and in the civilian arena," Tenet added.
He quoted statements from officials in China, Russia and an unnamed third country to "illustrate the power and the import of information warfare in the decades ahead."
"An adversary wishing to destroy the United States only has to mess up the computer systems of its banks by high-tech means," Tenet quoted an article in China's official People's Liberation Daily as saying.
U.S. concern over China as a potential foe is not new. Analysts at the Pentagon's Office of Net Assessment, the U.S. defense secretary's in-house think-tank, published a paper this year titled "Dangerous Chinese Misperceptions." In it, they pointed to what they called a Chinese hope to "leapfrog" the technology advances of U.S. armed forces.
In his prepared testimony, Tenet said unspecified foreign countries had begun to include information warfare in their military doctrine as well as their war college curricula "with respect to both offensive and defensive applications."
"These countries recognize that cyber attacks...against civilian computer systems in the U.S. represent the kind of asymmetric option they will need to 'level the playing field' during an armed crisis against the United States."
He said the "battle space" of the information age would "surely" extend to U.S. domestic infrastructure.
Tenet said many nations, including several potential U.S. adversaries, were reviewing their own growing dependence on civilian and military information systems to pinpoint vulnerabilities and try to patch them.
"We must do the same," he said. "If not, we could soon find ourselves at a significant disadvantage in addressing what may be the key security challenge of the next decade."
Tnet identified potential cyber-attackers as comprising everyone from foreign nations' intelligence and militaries to guerrilla forces, criminals, industrial competitors, hackers and disgruntled people.
Michael Pillsbury, a research fellow at the Pentagon's National Defense University who wrote an Office of Net Assessment Study of China's interest in information warfare, said Beijing had the world's largest program of its type.
"Judging by their military writings, they are saying that information warfare is the core of what they want to do," he said.
Written by Jim Wolf