EMP is a REAL threat
The Sun can give off an EMP that would take out electronics worldwide and send unprepared people and nations back 200 years. It happened when telegrams were the latest form of communication and burned up the wires. Today, we'd lose communication, vehicles, and anything dependent on electricity to work.
But an EMP can be created by a nuclear weapon or other device set off by an enemy, whoever that may be, and you can name some: N. Korea, Iran, Russia, China, ISIS.
So far the US Congress has refused to spend the few billion dollars to harden our electronic grid to prevent massive failure in the event of an EMP. Why? Some people say the elites, both Democrats and Republicans, already have their bunkers and hardened grids and don't care if most of the US starves in the first month. After a year, they can claim the whole country the rest of us left behind.