[rayiner]

That’s possible, but it’s a much more uncertain claim than the one being made above. The US became 50% richer than western europe by being an “isolationist MAGA wonderland” before reengaging with the world during the wars.

Did hegemony help the U.S. maintain that edge? Maybe! But I think that’s a harder claim to prove than suggested by OP. I think the direct cause of America keeping its edge in the second half of the 20th century is we have Silicon Valley. I can think of a mechanism how reserve currency status is an indirect cause: reserve currency status means the world invests in American banks, and banks then use that money to fund tech startups. But is that really what’s happening? As I said above, I’m unsure.

[geoka9]

Reserve currency status makes increasing money supply easier (the US has run large deficits and monetary expansions with less inflation than peers). "Petrodollars" create persistent demand for USD, independent of US domestic conditions - countries that import oil must earn USD (via exports, borrowing, or reserves) or hold US reserves in advance. Oil exporters, on the other hand, invest surplus dollars into US treasuries. This process absorbs US money creation and lowers US borrowing costs. This is an enormous advantage that the US is likely to lose if it continues on its isolationist course.