With nearly a month to go before the deadline for the US and China to reach a deal in their trade war, goodwill between the two countries appears to have been swept off the table in recent days.   China announced that it was once again restricting the export of critical minerals, prompting the US president, Donald Trump, to announce tariffs of 100% on US-bound Chinese exports, scuppering – at least for now - hopes that global economic turmoil could be averted. On Thursday, China’s commerce ministry announced enhanced restrictions on the export of rare earths, citing national security concerns.   China’s chokehold on the global supply chain of rare earths – minerals found in the Earth’s crust that are used to make everything from consumer electronics to cars to military equipment – has been a sticking point in the trade war. China produces more than 90% of the world’s processed rare earths and controls about 70% of the world’s mining.   Trump and Xi were expected to meet at the Apec summit in South Korea, which starts at the end of this month. There was also talk of Trump visiting Beijing in January. Those meetings seem less probable now.