Quantifying the Triple Bottom Line Impact of Geopolitical Disruptions on Maritime Logistics: A Decision-Support Framework for Sustainable Supply Chains

Abstract

Approximately 90% of EU–Asia trade volume transits through a small number of critical maritime corridors – the Suez Canal, the Strait of Hormuz, the Strait of Malacca, and the Bosporus. Recent geopolitical disruptions, from the 2021 Suez Canal blockage to the 2023–2024 Red Sea attacks, have shown that such events affect not only direct economic costs but also social welfare (supply security, port employment) and environmental performance (increased CO₂ emissions from rerouting). Existing sustainability frameworks in supply chain management typically treat geopolitical risks as exogenous shocks with linear, localized effects, failing to capture their propagation through hydro-dynamically constrained networks. This paper proposes a hybrid decision-support framework that integrates: (I) a simplified hydrodynamic module for estimating transit times through straits, (II) Mason signal-flow graphs for network-wide propagation of perturbations, and (III) multi-objective optimization to balance economic cost, CO₂ emissions, and social risk. The framework is illustrated using the 2021 Suez Canal blockage as an example. Preliminary results indicate that the total Triple Bottom Line impact of a six-day closure is 30–50% higher than estimates based on direct costs alone, due to propagation effects across Mediterranean ports and rerouted shipping flows. The model provides actionable insights for logistics operators, port authorities, and policymakers, and is aligned with current ESG reporting standards (GRI, SBTi) and EU resilience requirements (NIS2, CER, CSRD).