Defense Secretary Leon E. Panetta in a speech at the Intrepid Sea, Air and Space Museum in New York yesterday warned that the United States was facing the possibility of a “cyber-Pearl Harbor” and was increasingly vulnerable to foreign computer hackers who could dismantle the nation’s power grid, transportation system, financial networks and government.

“An aggressor nation or extremist group could use these kinds of cyber tools to gain control of critical switches,” Mr. Panetta said. “They could derail passenger trains, or even more dangerous, derail passenger trains loaded with lethal chemicals. They could contaminate the water supply in major cities, or shut down the power grid across large parts of the country.”

The most destructive possibilities, Mr. Panetta said, involve “cyber-actors launching several attacks on our critical infrastructure at one time, in combination with a physical attack.” He described the collective result as a “cyber-Pearl Harbor that would cause physical destruction and the loss of life, an attack that would paralyze and shock the nation and create a profound new sense of vulnerability.”

“The fact is that to fully provide the necessary protection in our democracy, cybersecurity must be passed by the Congress,”

“Without it, we are and we will be vulnerable.”

The New York Times quoted Secretary Panetta as saying:

“We’re not interested in looking at e-mail, we’re not interested in looking at information in computers, I’m not interested in violating rights or liberties of people,” “But if there is a code, if there’s a worm that’s being inserted, we need to know when that’s happening.”