Kazakhstan, for instance, according to a report from Bloomberg, has banned exports of wheat flour, of which it is one of the world’s biggest sources, as well as restrictions on buckwheat and vegetables including onions, carrots and potatoes. Vietnam, the world’s third biggest rice exporter, has temporarily suspended rice export contracts. Russia, the world’s biggest wheat exporter, may also threaten to restrict exports, as it has done before, and the position of the US is in doubt given Donald Trump’s eagerness for a trade war in other commodities.