Confirmation that preparations for Scott Morrison’s exciting hoedown with President Donald Trump included firm warnings by the Australian government to local aluminium producers, that they needed to rein in exports to the US, lands a wry milestone in the rising tensions between our most power ally and our biggest customer.

We have surely entered a weird place when an Australian government is warning Alcoa of America that it needs to rein in exports from Australia to its home market because the US President can’t get his golden-haired head around the law of unintended consequences.