A U.S. company has announced a $400 million deal with the United States Department of Defense amid soaring demand for domestically mined rare earth elements that are critical for both civilian and military technologies.

Low environmental standards helped China become the world’s low-cost producer of rare earths, but Beijing was also focused on helping the industry.

When China began its crackdown on the sector some fifteen years ago, there were hundreds of miners and processors. By 2013 ten producers controlled almost all mining. Today, there are just two state-owned giants: China Rare Earth Group and China Northern Rare Earth Group High-Tech (600111.SS).