The Great Schism refers to a conflictive religious event that occurred in the year 1054. In this conflict there was a mutual rupture and excommunication between the highest leader of the Catholic Church in Rome, the Pope or Bishop of Rome (together with the Christianity of the West), and the ecclesiastical hierarchies of the Orthodox Church (together with the Christianity of the East) especially the principal one of them, the Ecumenical Patriarch of Constantinople. Its direct antecedent is known as Schism of Photius.
It is because of the USSR and them taking over lots of country's and for example the Vietnam war and the Korean war. In both wars the communist's parties were supplied by the USSR. Another thing is that both country's kept on feeling threatened by each other.
In a democracy the government has less control over how people spend their time and what they believe. People are free to join clubs, political parties and other groups. In a dictatorship there's just one leader who has total control over the party and the country.