The birth rate is low in diverse industrialized nations because adults have come to see children as accessories and not blessings. One or two, fine. After that, they're a drag on the retirement fund or just take up too much time.
The world is increasingly self-centered. Moral relativism is the product of radical individualism, so this is not a surprise to anyone (especially the Vatican) who has been warning of the consequences for years.
I highly recommend "Veritatis Splendor", by Pope John Paul II. It was written in 1994, but the rest of the world is woefully behind the curve.
So far as Palestinians go - we can't compare the act of procreation with the manipulation/indoctrination that occurs afterwards. In a sense, if Italians are willfully saying "NO" to continuing the human species, what makes them less dangerous than a suicide bomber? Both acts - the will to destroy innocent life, and the will to prevent innocent life from existing, are evil. And abortion seems to bridge any gap between the two: There is both will to destroy innocent life, and the will to prevent innocent life from existing.
Look, I believe in large families, but I also believe in not arguing with facts.
I see no current equation between large families and virtuous social patterns. Right now, I see the opposite occuring in many locations. (hopefully as a temporary phenomenon).
My interest in the subject is from a rather odd perspective: decades ago I read an article in a science fiction magazine that predicted two things would happen by 2011...a population decline and the ability to keep humans alive indefintely. It was all based on some mathematical theory or the other and durned if it doesn't seem to be working out that way.