"Here begins our tale: The empire, long divided, must unite; long united, must divide. Thus it has ever been." This opening adage of Romance of the Three Kingdoms , China's classic novel of war and strategy, best captures the essential dynamism of Chinese geopolitics. At its heart is the millennia-long struggle by China's would-be rulers to unite and govern the all-but-ungovernable geographic mass of China. It is a story of centrifugal forces and of insurmountable divisions rooted in geography and history — but also, and perhaps more fundamentally, of centripetal forces toward eventual unity. This dynamism is not limited to China. The Scottish referendum and waves of secession movements — from Spain's Catalonia to Turkey and Iraq's ethnic Kurds — are working in different directions.