Regular readers of this blog know that I consider Mark Steyn’s book America Alone: The End of the World As We Know It to be a serious warning about our future as a society. I’ve offered two glimpses into the book already. It’s time for a third.

The first full chapter is called “The Coming of Age,” and it portrays a demographic challenge that the Western world is now facing. In short, Steyn tells us that we are aging rapidly in the West while the influx of Muslim immigrants is filling in the population gap.

Steyn says a nation, in order to maintain its current population, needs a fertility rate of at least 2.1 live births per woman. That’s where the U.S. is now, but old Europe, Canada, and Japan [which is connected with the West culturally and economically now] are well below that mark. Canada is the best at 1.48, Europe as a whole is at 1.38, with Japan coming in at 1.32, and Russia at 1.14. “These countries—or, more precisely, these people—are going out of business,” Steyn warns.

As usual, he has a fascinating way with words; in this case, he couches his warning in phrases that stick with the reader:

Unless it corrects course within the next five to ten years, Europe by the end of this century will be a continent after the neutron bomb: the grand buildings will still be standing but the people who built them will be gone. By the next century, German will be spoken only at Hitler, Himmler, Goebbels and Goering’s Monday night poker game in Hell. And long before the Maldive Islands are submerged by “rising sea levels” every Spaniard and Italian will be six feet under. But sure, go ahead and worry about “climate change.”

Meanwhile, Muslims—many of whom are radicalized—pour into Europe. At the time of his writing, there were twenty million Muslims in Europe. “That’s the equivalent of the Danes plus the Irish plus the Belgians plus the Estonians. You do the math.”

There are some statistics that may startle: “What’s the Muslim population of Rotterdam? Forty percent. What the most popular boy’s name in Belgium? Mohammed. In Amsterdam? Mohammed. In Malmö, Sweden? Mohammed. By 2005, it was the fifth most popular baby boy’s name in the United Kingdom.”

Steyn reviews all the foolish talk that came out of the 1960s and 1970s about a population bomb that was going to overwhelm us. That never materialized in the way the doom-and-gloom crowd wanted us to believe. In fact, their over-concern probably helped create the modern view that family is rather passé. The problem is, no one told the Muslims they were supposed to stop having children. And as they crowd into Europe and Canada, in particular, a reverse assimilation is taking place:

Instead of a melting pot, there’s conversion: a Scot can marry a Greek or Botswanan, but when a Scot marries a Yemeni it’s because the former has become a Muslim. In defiance of normal immigration patterns, the host country winds up assimilating with Islam: French municipal swimming baths introduce gender-segregated bathing sessions; Australian hospitals remove pork from the cafeteria menu.

Steyn also points out, “You don’t have to subscribe to the view that every Muslim is a jihadist nutcake eager to hijack a 747 and head for the nearest tall building to acknowledge that at the very minimum these population trends put a large question mark over the future.”

In the summer of 2006, a poll of British Muslims showed that only 17% believed any Arabs were involved in 9/11. What does that say about Westernized Muslims?

You can be perfectly assimilated when it comes to clothes, sports, pop music, the state of the economy, the need for transport infrastructure spending, and a million other issues, but on one of the central questions facing the world today 83 percent of the fastest-growing demographic in the United Kingdom does not accept the same reality as their fellow British subjects. And competing versions of reality is never a good recipe for social stability.

Steyn has a knack for the profound understatement.

Are we to fear for our future? To some extent, yes. But the warning is there for a purpose. It’s to alert us to change course and not accept a divided society. Our experiment in celebrating diversity must recognize when that diversity is a danger to us all. As Hobbes noted in one of my favorite Calvin and Hobbes cartoons, “I’m not sure if I can tolerate that much tolerance.”