I've seen many phoney trade wars come and go. This is the real thing

Donald Trump's decision to impose a 104% tariff on Chinese imports into the US - and China blasting back with 84% - has spooked the financial markets. The response is entirely rational. Over the past few decades, phoney trade wars have been commonplace. Rival nations have squared off against each other, indulged in a bit of sabre-rattling, but eventually agreed on a deal. Headlines that screamed "trade war looms" were quickly replaced by those that read "trade war averted". This time it's different. The battle between the US and China prompted by Trump's tariffs is no pretend trade war. It…