There is an eerie emptiness at the seat of US economic power. The US Treasury is in shutdown like much of the federal government. Most staff are furloughed as the world's finance ministers and bankers jet in for the International Monetary Fund annual meetings a few blocks away, their delayed flights handled by a small number of unpaid air traffic controllers. There is, however, one clear message the Trump administration is notably keen to get out, not so much for its domestic audience but for