This article argues the importance to humanity of understanding processes of social, political, and cultural integration and of attempting to forecast the results. It outlines the theoretical grounds for expecting future global trends to be integrative rather than disintegrative. It summarizes past empirical efforts to forecast their ultimate consequence—global unification—and it introduces some methodological cautions about such forecasts. There are underexamined implications to what is meant by unification, what is defined as a polity, and what are taken as units in constructing the empirical trends used in forecasting. Finally, the article points out that different types of resources can be used to construct power relations (and hence integration) and that therefore there is probably no single global unification but only different types of global unification.