From the border wall rhetoric to trade wars, Trump is effectively setting up the implosion of the dollar and couching it as pseudo nationalistic populism.
American sanctions are increasingly making the USD irrelevant.
Presently, some $2 billion worth of arms deals are hitting a snag over how settlement is to be made for defence transactions between Russia and India as US sanctions stand in the way. The issue has led to the US Dollar being dropped as a means of payment, with the Ruble and Rupee being considered as alternatives. The Economic Times