TOKYO – A funny thing happened in Asia this week: the region’s most important currency fell to four-year lows and Joe Biden’s White House didn’t say a thing.

Not the yuan, but the yen. China’s currency may have maddened former US President Donald Trump. Yet its use in global finance and trade, for now, pales in comparison to Japan’s.

And yet, the yen’s accelerating decline against the US dollar is meeting relative silence in Washington.

One possible reason is distraction. With Covid-19 still a live problem and political polarization sucking up most of the legislative energy, exchange rates aren’t an immediate priority. Yet the yen’s decline is surely a matter of fascination in Beijing, which is keen to see the yuan fall, too, to support the economy.

The yen’s movements could give President Xi Jinping geopolitical cover to halt the yuan’s strong rise this year, or even reverse it.