[eigenspace]

Yeah, that's a great point. But I will say that I think interest-to-GDP ratio is also a bit misleading here because what it doesn't capture is the uncertainty about future interest rates.

Because of the massive amounts of debt held by the USA, there is no option to just pay off the current debt. If there was a sharp increase in interest rates (or even just a long-protracted period of interest rates like the current one), the USA would have no option but to take out further debt at painfully high rates just to stay ahead of existing debts.

So even if interest payments aren't so bad currently, the large debt load is a large vulnerability.