The production and sales of electric vehicle lithium-ion batteries (EV LIB) have experienced rapid growth in the past decade, resulting in an extensive and intricate supply chain network (SCN). The SCNs orchestrated by different focal firms are interdependent due to the joint suppliers and customers. This interdependence, coupled with geographical segmentation, introduces vulnerability to the global EV LIB SCN. Focal firms need management insights from the multiplexity of the global EV LIB SCN to address the potential vulnerability. This investigation utilizes the empirical data regarding the supplier–buyer relationships of the top six EV LIB manufacturers in 2020 to construct the multilayered EV LIB SCN. Then, a focal firm-specific analysis is conducted to explore the multiplexity of the global EV LIB SCN, including identifying the influential firms, measuring the structure of SCNs led by different focal firms, and distinguishing the dependence and discrepancies of different focal firms’ SCNs. Furthermore, an SCN vulnerability (SCNV) index was designed to assess the vulnerability of such a multilayered SCN in two disruption scenarios, i.e., single-country blockade and intercountry blockade. The structural analysis can assist focal firms in allocating vulnerability-coping resources more effectively. Besides, the assessment of SCNV can assist managers in identifying potential risk sources beyond their own SCNs.

Global container liner shipping networks (GCLSNs) underpin world trade, yet their organization is increasingly reshaped by geopolitical fragmentation. Existing studies often model GCLSNs as single-layer networks, overlooking how carriers’ geopolitical affiliations structure both connectivity and disruption risk. This study constructs a weighted carrier–geopolitical multiplex network in which layers are defined by carriers’ geopolitical affiliations and coupled through shared port calls. Structural analysis reveals pronounced asymmetry in layer size, cohesion, and inter-layer dependence, with overlap concentrated in a limited set of shared hubs. Using the Red Sea crisis as an empirical stress-test scenario, we develop a load–capacity propagation model, incorporating intra-layer load redistribution, rerouting to substitute shared hubs, and inter-layer resource squeeze at same-port layer copies. Results show that direct losses concentrate in corridor-exposed layers, while indirect losses propagate selectively through bridge hubs, especially Singapore, Shanghai, Shenzhen, and Port Klang. Sensitivity analysis indicates nonlinear amplification when low tolerance, strong inter-layer squeeze, and elevated rerouting pressure coincide. These findings show that multiplexity does not imply resilience by itself; cross-layer connectivity buffers disruption only when spare capacity is distributed but amplifies vulnerability when it converges on a narrow set of shared hubs. The paper contributes a carrier–geopolitical perspective to shipping network analysis and a dynamic framework for studying disruption propagation in complex logistics systems.