The cause of the persecution and extermination of all religion and religious people in Albania, as well as the persecution of Moslems, Jews, Orthodox Christians, Catholic Christians, ETC., during the Cold War.
Many atheist states have persecuted the religious in the way many atheists have condemned Christians for doing back in the Middle Ages.
Need I say more?
Quote: "From year 1967 to the end of the totalitarian regime, religious practices were banned and the country was proclaimed officially atheist, marking an event that happened for the first time in world history."
Making an atheist state will not solve the problems of the world.