Since the Roman Empire, leaders have used ideology to organize the masses and instil amongst them a common consciousness, and equally to conquer, assimilate, or repel alternative ideologies. Ideology has been used to help create, safeguard, expand, or tear down political communities, states, empires, and regional or world systems. This book explores the multiple effects that competing ideologies have had on the world system for the past 1,700 years: the author examines the nature and content of Christianity, Islam, Confucianism, Protestantism, secularism, balance-of-power doctrine,...