If another country were to attack the United States with something like EMP (Electromagnetic Pulse) bombs and they effectively rendered most computers, automobiles, and computer assisted devices useless, would it spell complete doom for the country?

There’s the thought that if this scenario every played out, we’d supposedly be ‘back in the dark ages’ because we’re so reliant on technology and computers. Do you think this is basically true or could we start over again and how long would it take to get ‘back online’ or ‘reboot’ the country, so to speak?