A Theory of Strategic Bottleneck Migration

Abstract Defence resilience is often assessed through stocks, readiness indicators, recovery capacity, or local stability. These measures can miss a different problem: under compound stress, several finite and jointly necessary capacities may approach failure at different rates, so the operative constraint can change as the system is strengthened. This article develops a theory of strategic bottleneck migration. If q_i*(p) is the critical disturbance that exhausts strategic margin i within a specified horizon, system tolerance is the lower envelope q_f*(p)=min_i q_i*(p). For two operative constraints, q_f*=Q-|G|/2, where Q is their common resilience level and G is the selection gap that determines which constraint binds. This yields a local migration law and an adverse-substitution criterion identifying when an intervention mainly relocates vulnerability rather than increasing joint tolerance. A nonlinear five-state defence-resilience model illustrates the framework under compound shock, industrial reconstitution, social depletion, finite command authority, persistent exposure, and command delay. The model is not an empirical representation of any armed force or state; it is a computational stress test of the structural claim. The defence implication is that resilience planning should audit not only how much capacity is added, but which finite constraint becomes limiting next. Keywords: defence resilience; strategic theory; bottleneck migration; first passage; command delay; industrial capacity Scope note. The numerical model is a stylized single-system defence-resilience demonstration. It is not calibrated to NATO, any national armed force, or any specific conflict.