When Prime Minister Malcolm Turnbull goes to Washington this week to demonstrate his doe-eyed fascination with Donald Trump, we'll doubtless hear a lot about those tax cuts that are being funnelled into share buybacks (if you listen to CEOs and analysts) or creating trillions in investment and jobs (if you believe the Financial Review). But there's a major issue that needs to be at the top of Turnbull's agenda, even if he won't discuss it publicly. 

Apart from Trump's protectionist stupidity, which is risking a global trade war, one of the few clear policies of his chaotic administration is to cheapen the US dollar. And that is going to hurt the Australian economy, making the job of the Reserve Bank and Turnbull’s own government that much harder in the coming year. At the Davos circlejerk last week, US Treasury Secretary Steve Mnuchin touched off a currency firestorm when he said: