The subtitle of this book is, "The end of the world as we know it".
Steyn is a Canadian writer living in the US and has a regular newspaper column as well as a monthly column in National Review. His humor is ascerbic, but does not detract from the very serious posits he makes.
Probably the best description of the book is the back cover blurb by John O'Sullivan, editor at large for National Review:
"Mark Steyn is the funniest writer now living. But don't be distracted by the brilliance of his jokes. They are the neon
lights advertising a profound and sad insight: America is almost alone in resisting both the suicide of the West and the suicide bombing of radical Islamism. Our best chance for survival is that Mr. Steyn has done our thinking for us-and made it entertaining. Laugh? I thought I'd die."
Steyn's thesis is that the US almost alone is resisting the jihadists and radical Islam as well as the radical social policies of Yurrup. One of his central points is that Islam is going to triumph via breeding alone. European countries are below replacement birth rates and their need for labor, and tax-payers, is being met by immigration, much of it Islamic and much of that jihadist. The US, almost alone, is replacing it's native population from within and this has startling contrasts with other western countries. If you like PJ O'Rourke, you'll love Steyn.