By Mark Buckton A new report by the Atlantic Council has suggested that China – using a so-called dark fleet in conjunction with Russian and Iran – is effectively getting around existing sanctions on oil purchases from both countries. In the process, Beijing is also using the Chinese yuan to pay for shipments, in turn helping to prop up both the Russian and Iranian economies. Both the Iranian and Russian economies rely heavily on revenue brought about from oil exports, but for Moscow in particular, Western sanctions have disrupted their shipments severely in the two years since the start of th…