Way back in 1992, on a visit to Inner Mongolia, China's then-leader Deng Xiaoping uttered what has since proven to be a visionary declaration. "The Middle East has its oil, China has rare earths," he famously quipped. For a largely agrarian nation, which at that stage was still grappling with the aftermath and horrors of the Cultural Revolution, it was a bold step towards achieving his 1986 ambition of transforming China into a high-tech superpower. Deng envisioned a China with a dominance in rare earths that would transcend the Organisation of the Petroleum Exporting Countries' (OPEC) power over oil. Deng...