稀土共有17种金属元素，支撑从手机、笔电到战机与飞弹等关键技术。中国用约40年建立主导地位：开采约占全球供应的70%，加工几乎占90%，使美国短期内难以靠类似页岩油革命的创新迅速补上缺口。

美国重建供应链受成本与许可拖延所限：从发现矿藏到投产平均需29年，全球仅次于尚比亚。美国目前仅有一座稀土矿，国防部在7月以4亿美元入股MP Materials以扩建分离与磁材产能；但其规模仍小，预计年底钕铁硼磁体年产1,000公吨，还不到中国2018年产量的1%，即使未来10年扩至10倍也仅约达到中国的7%，且矿体缺乏镝、铽等重稀土。

企业另走三路：从尾矿回收（Phoenix Tailings位于新罕布夏的新厂于10月开张）、以替代磁材降低依赖（Niron Magnetics源于中国2010年减出口冲击，计划于2027年初开首座商业设施；特斯拉2023年宣称将移除稀土磁体但两年后仍广泛使用），以及倚重盟友。五角大厦在11月称将协助沙乌地的稀土加工点，10月美澳宣布未来6个月提供10亿美元推动采矿与加工。

Rare earths are a family of 17 metals that underpin modern electronics and defense systems. After roughly four decades of investment, China controls the supply chain, mining about 70% of global output and processing nearly 90%, leaving the US with a deep deficit that is unlikely to be closed quickly through innovation alone.

US rebuilding efforts face high costs and long permitting timelines: moving from discovery to production averages 29 years, second-longest globally after Zambia. The US has only one operating mine; the Pentagon’s July $400 million equity stake in MP Materials backs expanded separation and magnet output, yet MP’s expected 1,000 metric tons of NdFeB magnets by year-end is under 1% of China’s 2018 level. Even a 10× scale-up over the next decade would reach only about 7% of China, and US deposits are short on heavy rare earths like dysprosium and terbium.

Firms are pursuing three workarounds: extracting metals from mine tailings (Phoenix Tailings’ New Hampshire plant opened in October), developing substitutes (Niron, triggered by China’s 2010 export cuts, targets its first commercial facility in early 2027; Tesla’s 2023 aim to eliminate rare-earth magnets remains unmet two years later), and partnering with allies. The Pentagon said in November it will help finance a processing site in Saudi Arabia, and in October the US and Australia announced $1 billion over the next six months for mining and processing projects.