This assumes does not take into account what God will do. He has a way of dealing with wayward empires. Think Rome, Greece, Babylon, Ancient Egypt and others. His patience is limited.
Rome lasted in some form or another for 2000 years. In that time they had numerous times of decadence, but also numerous times of rebirth. Their eventual end was in 1453, as Turkish cannon (provided by a Christian Hungarian) shelled a breach in the walls of Theodosius, and the Janissaries stormed Constantinopole.