Indonesia has Islam, yet it's got a lot of problems. Likewise, the central Asian countries are muslim too - I mean, the situation there isn't as bad, but it's better
Really, banning foreigners would be all that's needed to solve the situation - then just increase the birth rate to something healthy, like 2.5-3 at minimum, to rebuild the population again. And, if Asian women aren't prepared to have kids, then just go for some frankenstinian artificial wombs...they have grown sheep in artificial wombs, so they could easily do it for humans...and when there are no morals in the world, there claiming this is somehow "immoral" or "unethical" is just absurd...Asian countries should have a win at all costs mentality