Maybe it's because we can't?
Face it, folks: the traditional powers of the world are declining, not because of any policy, but because of breeding, or lack thereof. The major powers of Europe and North America are not having children; they're embracing lifestyles that don't naturally produce children. This isn't like the last millennium, where Europe built empires on robust population growth and a need to find a place to put those people.
No, take a look at what populations are growing now: the Middle East, India, Mexico and Africa. Of those, only India has the resources to even potentially come close to be able to meeting its citizens' needs. That's what makes the rise of Islamic terrorism so scary. They have the numbers, and eventually they're going to go on the hunt for resources. Where are they going to find them? In the aging, declining hands of Europeans and Americans. Look at the Syrian refugee crisis. Look at our southern border, even. It's invasion by any other name, and why? Because they can. They have the manpower to do so.
Red China has a one-child policy. It was already huge to begin with, but even they saw that this, in the long run, was not sustainable. So now they've upped it to a two-child policy to get back to a sustainable population.
