You've got the situation. A group which does not generate children at replacement rate (or better) will eventually disappear, and be replaced by a group with a higher reproduction rate
You see it happen in Europe. The non-Muslim Europeans are not having children at anywhere close to replacement rate. The European Muslim population is growing rapidly, with Muslim women having many kids. Eventually, they will achieve political dominance.
It looks like a culture which allows women to enter the workplace (and choose not to have children) will over the long-run be overrun by a culture which mandates that its women produce babies, and does not give the women any choice in the matter
"a culture which mandates that its women produce babies"
According to THIS article, that's the Baptists. :)
Advanced weapon created by Western culture: