Supply Chain Reconfiguration by Cross-Border E-Commerce Platforms Under Economic Security Shocks: Partial De-Risking Versus Decoupling from the Original Supply Chain

Cross-border e-commerce platforms increasingly operate under economic-security measures that raise sourcing costs and impair order fulfillment, turning supplier reconfiguration into a joint pricing-and-sourcing problem. We develop a joint pricing-and-sourcing model applied to cross-border platform operations, with a low-cost, high-exposure original supplier and a higher-cost, more reliable alternative supplier. A per-unit tariff-equivalent cost t represents the policy-cost channel, an expected order-level fulfillment-loss rate q represents the fulfillment channel, and convex supply-chain switching costs determine the depth of reconfiguration. The model identifies the trigger for the transition from global sourcing (GS) to partial de-risking (DR) and the boundary between DR and decoupling from the original supply chain (DC). These analytical results are evaluated using a case-informed calibration to SHEIN’s low-value U.S. direct-shipping apparel setting. The results show that, under the baseline calibration, the GS-to-DR trigger is t=5 when only the tariff-equivalent cost shock is present and q≈0.282 when only the fulfillment shock is present. Across the case-informed t-q domain, DR accounts for 82.11% of evaluated combinations and DC for 0.023%; lower switching-cost intensity and a smaller alternative-supplier cost premium expand the DC region. Robustness analyses examine alternative demand specifications, sourcing granularity, capacity constraints, switching-cost forms, supplier risk, failed-order cost incidence, and supply-chain structures. By distinguishing the trigger for diversification from the depth and boundary of subsequent reconfiguration, the study clarifies why partial de-risking can emerge as a distinct strategy between global sourcing and decoupling from the original supply chain and provides decision benchmarks for supplier diversification, regional fulfillment, and resilience investment.