Without Electricity... Can You Live Like It's 1880!? 

THE MOST SERIOUS THREAT WE FACE IS...
The Power Grid being hacked/disabled if at war.

“If the grid went down for a long enough time…
  90 percent of the U.S. population would die  from starvation, lack of water, and social disruption.  We are talking about total devastation.”
-- Ambassador Henry Cooper, Former Director of U.S. Strategic Defense