The protests in Iran, now in their third month, are a historic battle pitting two powerful and irreconcilable forces: a predominantly young and modern population, proud of its 2,500-year-old civilization and desperate for change, versus an aging and isolated theocratic regime, committed to…

Ibn Khaldun, the 14th-century North African scholar, wrote that empires tended not to last beyond three generations. The founders of the first-generation are rough men united by hardship, grit and group solidarity, a concept he called asabiyyah. The next generation preserves the achievements of…