World politics is entering a new phase, in which the great divisions among humankind and the dominating source of international conflict will be cultural. Civilizations--the highest cultural groupings of people--are differentiated from each other by religion, history, language and tradition. These divisions are deep and increasing in importance. From Yugoslavia to the Middle East to Central Asia, the fault lines of civilizations are the battle lines of the future. In this emerging era of cultural conflict the United States must forge alliances with similar cultures and spread its values wherever possible. With alien civilizations the West must be accommodating if possible, but confrontational if necessary. In the final analysis, however, all civilizations will have to learn to tolerate each other.