Agree, Pope John Paul II, not Pope Benedict.
Look, anyone who us not blind can see that nothing is currently working to raise the birthrate...in places as diverse as Italy and Russia.
The underlying cause is not that the world population is suddenly more degenerate that in the past.
If that were so then the birthrate in certain Moslem countries should also be in the pits and it's not. Aren't Palestinians busy breeding suicide bombers? Are they more virtuous and loving than Italians?
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.