Obviously, I am not claiming that atheism was the main reason people fled their own countries. But atheism, since it makes a personality cult much easier, makes it virtually impossible to put a check on bad ideas of the God-substitute--e.g. Hitler: anti-Semitism, as well as of course starting World War II;    Mao:   the Great Sparrow Campaign, if not the entire Great Leap Forward.

And nobody is claiming non-atheistic states are perfect. Nobody is advocating a theistic state, for instance. Obviously, the best idea is neither a theistic nor an atheistic state.

But the fact remains that atheistic states have a perfect record of failure; non-atheistic states do not.