Assessment of critical minerals supply chain for the United States in perspective of trade restriction by foreign countries

In this study, major global producers of the 50 critical minerals designated by the United States government in 2022 were investigated to analyze the supply chain vulnerability to the United States by screening a single foreign country’s role at extraction, processing, and trade. The “freedom in the world” indicator was integrated into these stages to calculate the score of potential risk (Spr), which this study introduced to assess the likelihood of supply chain disruptions. The commodities with high scores of Spr (Tier 1) matched the ones with existing export-controlled critical minerals imposed by China until 2023, which include gallium, germanium, graphite, rare earths, and tungsten. In order of Spr, the remaining minerals were classified into tiers of potential supply risk: Tier 1 (Spr ≥ 50%) indicates high risk (bismuth, magnesium, antimony, and tellurium); Tier 2 (50% > Spr ≥ 32%), moderate risk (indium, vanadium, arsenic, tantalum, and zirconium); and Tier 3 (Spr < 32% with high potential risk if geopolitical conditions change), low to sensitive risk (niobium and platinum). The effectiveness of the approach was further demonstrated by the 2024 export controls implemented by China on antimony, bismuth, and magnesium, which were all classified as Tier 1 prior to the restriction. A short list of critical minerals in this study may be monitored although the current risk is low. The Spr of critical minerals provided an indicator in determining the levels and sources of potential supply risk as well as informing mitigation strategies in the years ahead.