China and Japan get made out to be more atheist than they are cuz ignorant folks tend to slot Chinese Folk Religion and Shintoism under atheism, due to the lack of a central divine power. Taking that into account, those two nations are religious as any other. China endorses CFR, and, officially at least, promotes freedom of religion, but doesn't let communist party members retain affiliations with any organized religion.
Estonia, on the other hand, is a majority atheist nation by choice and not by misnomer. There are a handful of nations with close to that percentage, but Estonia has taken particular cultural pride in that fact, and is indeed a nation, at least attempting, to revel in radical scientific progress.
Even Estonia, however, is not majority Atheist, but majority Agnostic. Of the two thirds of the population who say religion plays no important role in their lives, more than half of those still believe in the possibility of higher spiritual powers.
It's worked out okay for Estonia, though their reliance on cutting edge technology has caused them some problems. It wasn't too long ago that they started to make a transition to a direct democracy model through the internet, and got themselves hacked right quick. Russia has been known to screw with Estonia by hacking it on a regular basis. The few religious folks that remain in Estonia, not surprisingly, tend to be ethnic Russians.
>The Soviet Union
Stalin was ordained by the Orthodox Church, which was officially recognized by the Soviets as a state sponsored religion.
>China
Chinese folk religion temples, CFR temples everywhere.
>Nazi Germany
Christian as fuck, banned atheism and secular schools.
>Cambodia
95% Buddhist.
>Iraq
Fucking sunni muslim government under Saddam.