Ironic. Iran forces ultra radical, orthodox islam on the citizens for basically one sole reason - to increase the birth rate, since Iran is 60% ethnic Persians and 40% Kurds, Azeris and Arabs who hate the Persians, reproduce at a faster rate and will start a civil war the minute they think they have a chance of winning. And yet Persians in Iran have one of the lowest fertility rates in the entire world. Iran is doomed to dissolve as a state within our lifetime because of this.

Meanwhile, North Korea which has been exclusively atheist for generations, has a birthrate that is perfectly fine.