The US has been trying to reduce the usage of the USD as a reserve currency (it's the largest such currency but not the only one - EUR, GBP and JPY are also used) due to it not having any real benefit to the US while exposing its economy to the effects of financial crises around the world, which tend to lead to countries purchasing dollars and driving the price up which makes imports more expensive.
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Ben Bernanke (ex-FED Chairman) - The dollar’s international role: An “exorbitant privilege”?
https://www.brookings.edu/blog/ben-bernanke/2016/01/07/the-d...
> A great deal of U.S. currency is held abroad, which amounts to an interest-free loan to the United States. However, the interest savings are probably on the order of $20 billion a year, a small fraction of a percent of U.S. GDP, and that “seigniorage,” as it is called, would probably still exist even if the dollar lost ground to other currencies...
> The safe haven aspect of the dollar is actually a negative for U.S. firms, since it implies that they become less competitive (the dollar is stronger) at precisely the times that global economic conditions are most difficult.
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The ‘reserve currency’ myth: The US dollar’s current and future role in the world economy
https://www.ussc.edu.au/analysis/the-reserve-currency-myth-t...
> This safe-haven bid for US dollar assets means that the US dollar often behaves in ways that seem counter-intuitive relative to US economic fundamentals. As Figure 2 shows, the US dollar appreciates in response to economic policy uncertainty. A 1 per cent increase in the Global Economic Policy Uncertainty Index raises the real value of the US dollar by 0.2 per cent, controlling for relative interest rate, inflation and economic growth differentials with the rest of the world.
> The appreciation exacerbates trade tensions between the United States and the rest of the world by weighing on US export competitiveness, setting in train a protectionist spiral.
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The IMF already has a global reserve asset called the Special Drawing Rights:
https://www.imf.org/en/About/Factsheets/Sheets/2016/08/01/14...