China has less than 5 per cent of the world’s known reserves of nickel. So as it has done with cobalt in Congo and lithium in South and Central America, it looked overseas, to a country eager for foreign capital and technical know-how. “China’s been ready and willing to invest in places where the US, European, even the Canadian, Australian companies haven’t gone,” said Michelle Foss, a fellow at Rice University’s Baker Institute Centre for Energy Studies, who has researched China’s growing hold over nickel. Onshore processing Indonesia has become an enthusiastic partner. President Joko Widodo is determined to wean...