This article examines the legal status of critical oil infrastructure as dual-use objects under international humanitarian law (IHL) and evaluates the adequacy of existing civilian protection frameworks in the context of the United States–Iran conflict. Employing normative legal research with statute and conceptual approaches, this study analyzes the application of the principle of distinction under Articles 48 and 52 of Additional Protocol I to the Geneva Conventions. The findings reveal that oil refineries, export terminals, pipeline networks, storage facilities, and offshore oil facilities cannot be classified as military objectives merely based on strategic, economic, or war-sustaining value. Rather, their classification requires restrictive, evidence-based assessment of actual military function and definite military advantage. Furthermore, the existing IHL framework, when applied through a narrow object-centred approach, provides insufficient civilian protection for such infrastructure. A systemic reinterpretation is necessary. This reinterpretation must incorporate reverberating effects, service dependency, environmental consequences, cumulative harm, and post-strike deprivation into proportionality, precautions, and military necessity assessments. This article concludes that critical oil infrastructure remains presumptively civilian unless specific components demonstrate concrete contribution to military action, and that civilian protection must be reinterpreted to reflect the realities of contemporary energy-dependent warfare.