Although cyber weapons are not currently advanced enough to take out the entire U.S. electrical grid, they may progress to that point within the next few years, at which time we could be "talking about an equivalency of a weapon of mass destruction," former vice chairman of the Joint Chiefs of Staff James Cartwright said on Tuesday.

Speaking at the Center for Strategic and International Studies in Washington D.C., Cartwright called the likelihood of an opposing nation-state taking out the U.S. grid "very remote," but added that that possibility is only "two to five years off," according to the AFP.

"A nuclear weapon could knock out the electrical grid in any city," he said. "Cyber could knock it out in the entire country -- in milliseconds."

However, Cartwright stressed the difference between cyber warfare and more simple acts of hacking, which have plagued a number of nations and businesses in 2011.

"It's a very difficult thing to do," the AFP quotes him as saying. "It's not some 19-year-old sitting at a keyboard."

Cartwright's warning comes just one month after experts cautioned that cyber attacks which target large-scale industrial control system are highly feasible.

Security researchers in October were able to successfully replicate last year's high-profile attacks on computerized industrial control equipment in power plants in Iran – breaches that were known at the time as being so sophisticated they could only have been pulled off by a nation-state or a well-financed group of investors, according to the Associated Press (News - Alert).

One of the researchers, Dillon Beresfordr, identified as many as a dozen vulnerabilities in the same kind of industry controllers as those used in Iran. What is worse, Beresfordr did it on his own, in just two months, while investing only $20,000 in the project.

These types of attacks could be used to target power plants, correctional facilities and other U.S.-based institutions that rely on industrial controllers.

Cyber crime has also had a major impact on the enterprise space. A recent PricewaterhouseCoopers (News - Alert) study found that nearly one-quarter of all economic crime perpetrated against businesses in 2011 was of the cyber variety.

Beecher Tuttle is a TMCnet contributor. He has extensive experience writing and editing for print publications and online news websites. He has specialized in a variety of industries, including health care technology, politics and education. To read more of his articles, please visit his columnist page.

Edited by Jamie Epstein