System Structural Analysis of the Influencing Factors in China–Iraq International Energy Cooperation on Natural Gas

China–Iraq international energy cooperation on natural gas constitutes a critical component of energy diplomacy under the Belt and Road Initiative. This study develops a multidimensional analytical framework encompassing geopolitical, economic–market, legal–policy, resource–technology, social–environmental, and bilateral–institutional dimensions. Subsequently, an integrated fuzzy DEMATEL-ISM model is employed to investigate the hierarchical structure and transmission pathways of influence among these factors. The findings reveal that the multiple factors can be classified into four clusters (driving, linkage, independent, and dependent), each exhibiting distinct roles in system evolution. Meanwhile, the model identifies a six-tier hierarchical structure, with directed pathways transmitting from deep-rooted factors through intermediate nodes to surface-level outcomes. Surface-level factors occupy the upper tier and directly shape cooperative performance, while intermediate-level factors act as transmission conduits that relay and transform deeper influences. Deep-level factors, including great-power rivalry, resource endowment, and market demand, form the system’s foundational layer. They remain immune to influence from upper tiers and thus require strategic governance to fundamentally ensure enduring cooperation sustainability. Consequently, policy priorities should center on deep-level drivers, complemented by targeted adjustments to intermediate and surface factors. This study offers a novel multi-level structural analytical lens and provides actionable policy recommendations to enhance cooperative resilience under the Belt and Road framework.