In my opinion, the second chapter is the best reasoning for being a prepper. It is apolitical and well reasoned. It is out as a 2nd edition as of 2008, but was drafted before the Great Recession developed.
It could use an update because Peak Oil plays a more immediate role than warranted by today's production technology and US production. I personally think fresh water is likely to be the most critical shortage.
The rest of the book is a great overview of short and long term survival needs and skills.