As Donald Trump’s trade war escalates, a lot of farmers are worried. Trump was elected, in part, on a promise to put America’s interests first and crack down on what he characterises as a world trade system rigged against the US. But until recently the president has acted like many of his predecessors – talking tough on the campaign trail but backtracking in the White House. All that has changed. Week after week, Trump’s trade talk has seemed to harden.