ソース:[1] US Defense Department to buy cobalt for up to $500 million (https://finance.yahoo.com/news/us-defense-dep ...)[2] US drafts $500 million plan to rebuild cobalt stockpile, targeting non-China supply - The Oregon Group - Critical Minerals and Energy Intelligence (https://vertexaisearch.cloud.google.com/groun ...)[3] The U.S. Critical Minerals Push: Strategic Opportunities in Mining and Midstream Processing (https://vertexaisearch.cloud.google.com/groun ...)