So in other words, long term, it's backed by toilet paper.
https://acaa.org.uk/blog/frozen-assets-and-freezing-temperat...
The threat of devastation works better on countries that aren't already completely devastated by decades of internecine conflict anyway. It also works better against the non-theocratic adversaries that are legitimately concerned for their own corporeal wellbeing (Qaddafi, Saddam, KJU, Assad).