Jamie Dimon says US economic and military strength underpins the dollar's reserve status. The Iran war shows the US isn't ready for a prolonged war. The dollar could eventually lose its status as the world's reserve currency if the US fails to maintain its economic and military dominance, JPMorgan Chase CEO Jamie Dimon said. The dollar remains the world's dominant reserve currency, accounting for about 57% of global foreign-exchange reserves, down from around 70% at the turn of the century. For Dimon, maintaining America's economic and military edge also means reducing its dependence on potential adversaries for strategically important goods.