The twilight of cheap abundant energy is in many ways the dominant theme of global politics in our time, but another factor is coming to play an important role as well — the waning of America’s global empire. Impolite as it may be to mention the relation between America’s gargantuan military budgets and global network of bases, on the one hand, and the vastly disproportionate share of the world’s energy, materials, and industrial products Americans receive, on the other, the reality of America’s empire and the course of its decline have to be factored into any sense of the future ahead of us, and to do that, the nature of empire as a social, political, and economic reality has to be explored.