The U.S. dollar has long held its position as the world's primary reserve currency. It's also considered a safe-haven currency because of America's robust economy and stable political system. But according to renowned global investor and economist Marc Faber, the greenback's dominance is now on shaky ground. "I think that the U.S. dollar will become over time — not tomorrow, but over time — a worthless currency," he said in a recent interview with Stansberry Research. Faber is highly critical of