Anchored by Jake Tapper, The Lead airs at 4 p.m. ET on CNN.
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Imagine that with a few keystrokes by a foreign enemy armed with nothing more than a laptop, an American city is suddenly plunged into darkness. Air traffic controllers watch their radar screens go black. A critical banking system is taken down, causing a financial crisis. Hospitals cannot operate. Clean water is no longer available.
With the looming specter of cyber warfare, that is the kind of threat the United States faces from enemies abroad, according to warnings from top intelligence and military officials.
It is the kind of thing that keeps former Secretary of Defense Leon Panetta awake at night:
"The collective results of theses kinds of attacks could be a cyber Pearl Harbor. An attack that would cause physical destruction and the loss of life," Panetta said in October 2012.
On Friday, The Wall Street Journal reported that Iran hacked U.S. oil, gas, and power companies. The hackers are far enough inside, that people are starting to get really worried.
"Power grids, electricity, communications, transportation - the critical infrastructure that lets us to do our day-to-day jobs, it's all run by computers." said Shawn Henry, former executive assistant director of the FBI.
"If adversaries ... are able to disrupt some of the hardware or software, disrupt the actual control systems, they can have devastating impact," said Henry.
A lot of cyber protection falls to private companies because "the government is not out with a giant shield over the network, for obvious reasons, people don't want, for privacy reasons, the U.S. governments [in] the networks monitoring the traffic," said Henry.
Though the government does share intelligence with the private sector to help them better protect themselves.
"A good offense will always beat the defense," said Henry. "The most sophisticated adversaries we've seen, have been able to infiltrate most defenses."
Skeptics say the threat of cyber warfare is hype from defense contractors who want to capitalize on people's fears, and sell their products to governments and private industries.
"This is clearly a legitimate threat," said Henry. "There's been theft of intellectual property and espionage, but there also are adversaries who are calling for electronic jihad against U.S. infrastructure."
The Pentagon acknowledges that the U.S. has conducted cyber attacks, like the Stuxnet virus that penetrated the Iranian nuclear program. Attacks could be seen as countries seeking retaliation for the U.S. taking action.
Henry said he believes there need to be discussions between governments about the parameters of such attacks.
"The red lines need to be defined, and there needs to be a strategy for how to combat this," said Henry. "This can quickly escalate and become traumatic and tragic for many people, if it's not handled in the appropriate way."