[Aquinasfan]

Between infertility and abortion (the former sometimes caused by the latter), many countries will not have the workers, military, or brain-power needed to sustain themselves.

You seem to have forgotten the most significant factor.

[Desdemona]

You seem to have forgotten the most significant factor.

The lack of single people of the opposite sex (that would be male) with the guts to ask one out on a date? Otherwise, there are many women in their child-bearing years out there who would be more than happy to help out.

[Polycarp]

Between infertility and abortion

You seem to have forgotten the most significant factor.

As I said above, "Giovanni Battista Montini was right!!!"

Of course, Giovanni Battista Montini is otherwise known as Pope Paul VI, best known for his encyclical Humanae Vitae, which predicted (prophecied?) all this mess in the first place.