To a hard-nosed “realist” reader, the scenarios of growing international coordination and pragmatic institution-building described in the preceding chapters will no doubt seem like an idealistic fantasy. From such a reader’s perspective, we are likely to see a very different sort of future unfold in the second half of the twenty-first century – a geopolitics based on continued rivalry, arms races, and frantic competition for dominance among China, the United States, and Russia, alongside the restless jockeying of new powers like India, Brazil, Japan, and perhaps a more tightly consolidated EU. Some prominent scholars of international relations subscribe to this view, and this chapter summarizes their arguments about the prospects of geo-strategic affairs over the coming decades. In such a scenario of “business as usual,” unfortunately, the planet-level instruments for managing our four mega-dangers would be distressingly weak, and the opportunities for large coalitions of nations to come together successfully in coordinated, long-range projects will be rare.