In December 2010, an American historian published an essay that would be cited for years to come. In a piece contributed to the nonprofit independent outlet “TomDispatch,” he forecast that the United States would lose its superpower status around 2025, far earlier than the then-mainstream view of 2050, and predicted that “riding a tide of political disenchantment and despair, a far-right patriot who seizes the presidency with thundering rhetoric will demand respect for America’s authority an...