Critical minerals have become a central concern of supply security, yet in landlocked Central Asia the geoeconomic value of mineral resources depends not only on extraction and processing but also on the ability to move output through reliable, substitutable, and financeable corridors. This article explains how competition over critical minerals extends into corridor competition and assesses the conditions under which Iran can convert locational advantage into operational centrality. It develops an analytical framework linking geoeconomic instruments, networked interdependence, regional agency, corridor performance, transaction risk, and traceability, and distinguishes four stages: asset, capacity, capability, and realized flow. Empirically, the study combines structured documentary comparison, multi-source secondary data, process tracing, and an embedded case study of Chabahar over 2021–2026. The findings show that mineral competition does not create corridor rivalry from zero; rather, it raises the strategic value of routes able to attract and retain flows under acceptable levels of cost, time, reliability, legal-financial risk, and informational traceability. Central Asian agency also depends on usable, not merely announced, alternatives. Iran possesses a genuine southern option, but available evidence does not support claims of established centrality. Its position is better understood as conditional centrality: geography and infrastructure create entry potential, while sustained mineral flows require measurable improvements in border performance, transaction conditions, multimodal connectivity, and end-to-end traceability.