Here are some quotes:
History shows that when a culture ceases to value children above all, when traditional marriage and family structure is seen as merely an option, that culture will cease to have enough offspring to sustain itself.
...these societies expire from lack of manpower, which itself is a manifestation of a lack of the will to live.
While we late moderns eat, drink and make merry, the Harvard scholar lamented, "very little public knowledge of the nearness, the inescapability or the seriousness of this impending crisis exists."
Along the same lines, there is a DVD called Demographic Winter: The Decline of the Human Family. It's trailer is absolutely chilling.
If even half of this stuff is true, it's a serious issue. If all of it is, we're in big trouble...