Global stock markets have plummeted after China said it would strike back at US President Donald Trump with additional tariffs of 34 per cent on US goods, escalating a trade war that has rattled investors and fed fears of a coming recession. Wall Street was down sharply on Friday following the Chinese response, which would be imposed from April 10, after the Trump administration’s sweeping levies knocked off $US2.4 trillion ($A4 trillion) from US shares. In the stand-off between the world’s two biggest economies, China also announced controls on exports of some rare earths while Trump also doubled down, vowing...