Abstract
Debates on the contingency of history have largely focused on the history of life. This article targets the supposed contingency of human history. It does not defend a global claim about the overall contingency of history. Rather, it aims to identify and explain the difference between robust and fragile historical trajectories. It does so by considering a set of contrasting cases and identifying critical differences among the cases. The analysis shows that one important source of contingency is the historical emergence of command-and-control institutions; one important source of robustness is the existence of population-level processes structured by relatively stable institutions.