Abstract
Analysis of persistent and recurring episodes of large-scale collapse of the fire service in New York City suggests a striking inverse to Granovetter's ‘strength of weak ties’ analysis of social system integration: that hierarchical paramilitary systems can become fatally unstable if locally based, strong self-interacting equivalence classes of units are unable to answer the vast majority of calls for service without assignment of units from other classes. A simple network-based model finds that an incremental increase in the probability that units must be shared between geographically centered classes leads to a sharply nonlinear, system-wide ‘phase transition’ from stability and localized demand to instability and a ‘delocalized’ service demand. Implications are explored for the continuing deterioration of the fire service in New York City and its considerable consequences for both public health and public order. More general questions of the interaction of extended but integrated social systems with paramilitary hierarchical structures are also examined.