According to this the US nominally ran a current account surplus until the 1970s: https://www.bea.gov/sites/default/files/2024-03/trans423-ann...

Which is what you'd expect if you're exporting more than importing. Perhaps you meant by some other accounting, which is what I was alluding to regarding the distortion caused by gold convertibility. Ceteris paribus, the trade & account balance will zero out over time in the absence of some kind of regulatory or similar distortion. China doesn't need to be a net importer to become a reserve currency, but if they became one (deliberately or otherwise) and allowed their currency to float than in time their exports would tend to fall and they'd likely become a net importer, at least if they became the dominant reserve like the US. (If they didn't float, you'd get a mess like the US had.) The reserve status can drive the balance of trade toward net importing. Which is precisely why China doesn't really want to become a global reserve currency. They'd certainly like the soft power that would bring, but they don't want the domestic employment disruption the US suffers from. That doesn't stop them from wanting their cake and eating it, too; they can try, but nobody really believes they could, so nobody takes it seriously. Though it's not necessarily an all or nothing deal. I'm not sure the world needs a single reserve currency as dominant as the dollar. We have markets to arbitrage and balance currency valuations, including future expected valuations. A singular dominant reserve currency is helpful to reduce friction, but less so when you have huge, global currency and currency derivatives markets constantly trading.

The Louvre Accord and the Plaza Accord before that, in the 80's, are of a different time and place.