FT story on how "US is scrambling to resume production of raw materials vital for defence equipment and green technology in response to rising fears about Chinese domination of the sector."
The point to be clear on: China dominates current production of rare earths (95-plus percent) but in no way has a dominant supply/reserve position. The world has simply allowed China to achieve its dominant production position by abandoning their own mining efforts. Why? Very expensive and very environmentally damaging.
Rare earths are a collection of 17 metallic elements with similar chemical make-up. They present unique magnetic and optical properties that make them highly useful for miniaturization, lasers and energy efficiency. There are considered strategic because of their applications in high-tech industries, to include weaponry.
No one much cared about China's domination of production, until the South China Sea dust-up with Japan led China to allegedly slow exports to Japan (not entirely clear what happen, but impressions were made). China has also recently signaled that it will cutback on exports to make sure it has enough for its own burgeoning domestic demand.
Now, according to the article, we've got people in Congress dreaming of US self-sufficiency on this score, which will be--like most things in this globalized economy--virtually impossible to achieve. Long ago, the US was the dominant global producer, but we abandoned the effort due to environmental and cost realities. Article says the last US mine closed in 2002 and is looking for $500m to reopen. Those guys should send a thank-you letter to Beijing, because I'm betting they'll get their investment soon.
Obviously, if the material is considered strategic, there's good logic for mining at multiple sources. I would consider this a reasonable space for cooperation with long-time allies so that we're not all doing this in the most expensive manner possible.