Possibility for systematically targeted attacks in disabling a whole country?

The concept of disabling the whole country by initiating cyber attacks first appeared in an article called “A Farewell to Arms” by a Wired magazine written John Carlin in 1997. After 11 years, we are all much more dependent on technology than we were than, and the possibility for such a scenario are more and more plausible. Also known as “firesale” ' (popularized by Hollywood) it involves disabling services such as communication, power, traffic and defense capabilities of a country by systematically made cyber attacks. And since the cyber warfare was recently compared to events such as Manhattan Project and 9/11, this is a viable possibility.