There’s nothing stopping a non-US bank having a vault full of actual US currency backing its US-denominated accounts. And settling transactions by sending physi

There’s nothing stopping a non-US bank having a vault full of actual US currency backing its US-denominated accounts. And settling transactions by sending physical cash on a plane. It is more expensive than using a US bank which makes it much more electronic, but has the advantage that the US government cannot stop it except by shooting down that plane