Structural Fragility in the French Fifth Republic: A Deterministic Extrapolation Framework with Trigger-Sensitivity Analysis and EuroArea Network Implications

his repository contains a structure-preserving adaptation of a nine-pillar institutional fragility framework to the French Fifth Republic, originally developed for the United Kingdom (Cohen, 2025). The model implements a deterministic extrapolation methodology to assess whether the observed multi-domain drift of structural indicators (fiscal, institutional, social, healthcare, security, and digital) is internally consistent with long-run system stability, or whether it implies approach toward trigger-defined “pre-failure” states under the framework’s own logic. The analysis treats fragility as a phase-space geometry problem rather than a forecasting exercise. Each pillar is normalized to a bounded [0,3] scale and extrapolated using linear drift estimated from 2020–2025 data. Systemic risk is evaluated through two trigger mechanisms: (i) persistence of elevated composite fragility, and (ii) concordant failure of a Stability Triad (Pluralism Retention, Institutional Trust, Counter-Extremism Integrity), representing synchronized loss of social contract, legitimacy, and security neutrality. A structured stochastic perturbation layer is included solely for trigger-sensitivity analysis, quantifying the local volume of state space in which correlated tail shocks induce early threshold crossing. No probabilistic forecasting claims are made; Monte Carlo simulations are used to explore coherence loss under perturbation, not to estimate real-world event frequencies. The framework is further generalized conceptually to a Euro-area network topology, modeling coupled national fragility manifolds and examining whether France functions as a leading-indicator (“canary”) node or a potential systemic amplifier (“superspreader”) through degradation of shared shock-absorber capacity (e.g., ECB credibility, fiscal coordination). This work is intended as a transparent, reproducible diagnostic instrument for institutional brittleness and regime-transition risk, emphasizing deterministic drift, trigger geometry, cross-pillar coupling, and network contagion over point prediction.