Every few months, a consignment of car parts rolls off a production line in an industrial town on China’s mighty Yangtze river. The engines and chassis are sent to a different factory to be half-assembled into what is known as “knocked down” form, before being loaded into containers and shipped to their final destination — Iran.
But these half-built cars are not paid for in cash. Instead, they are exchanged for containers of Iranian copper and zinc to feed China’s vast metals industry.