They were once allies and twin pillars of U.S. strategy in the Middle East, but Sunni Saudi Arabia and Shia Iran became mortal enemies after 1979. How did it unfold, and what was America's role? Here Kim Ghattass shows how these nations used and distorted religion in a competition that went well beyond geopolitics, feeding intolerance, suppressing cultural expression, and encouraging sectarian violence from Egypt to Pakistan. This "sweeping and authoritative history" (NYTBR) traces how the war for cultural supremacy led to Iran's fatwa against author Salman Rushdie, the assassination of countless intellectuals, the birth of groups like Hezbollah in Lebanon, the September 11th terrorist attacks, and the rise of ISIS.