This article develops a general theory of state dynamics to explain national evolution including growth, stability, stagnation and decline. Existing literature on national development covers modernization, institutionalism, state capacity, world-systems and collapse theories, but focuses on partial determinants and lacks a unified formal framework. For decades, scholars across political science, historical sociology and comparative political economy have proposed diverse explanations for national evolution, yet none have constructed a logically closed, axiomatic and quantifiable framework that integrates all core influencing factors. To address this critical gap, I propose a parsimonious dynamic model: G = S I (P + E - C), where national growth G is determined by state scale S, institutional stability I, periodical environment P, expansive capacity E, and systemic consumption C. This framework integrates structural, institutional, temporal, and social factors into a single dynamical system, reveals the non-linear logic of national resilience and collapse, and identifies a universal threshold: expansion persists when E > C, while decline becomes inevitable when C chronically outweighs E. The theory transcends fragmented existing accounts by providing an axiomatic, quantifiable, and historically portable structure for understanding long-run state evolution. It contributes a unified foundational model to political sociology and comparative political development, with broad implications for studying state collapse, great power transition, and sustainable governance.
Zhiye Zhang (Fri,) studied this question.