Oh. Like the pallets of gold, cash, jewelry and ??? sent by airplane from Washington to Iran a few years ago by Obola’s “scandal-free” administration’s State-CIA-NSA-DOE-DOD?
It is not as hard as you might think.
Trade was conducted for a very long time with gold and barter. The Arabs especially had a system that amount to letters of credit and a bank of settlements. I have read that they still do among small traders that operate in the old ways.
The way it works is to maintain identical ledgers and debit and credit accounts on those ledgers for international transactions. In the event of extremely large transactions the settlement might need to be in gold from reserves transferred from one account to another.
At some point, there is a clearing of accounts and actual gold is tranaferred from one to the other. A process like this actually occurs in the Federal Reserve of New York vaults where nations store their gold. the bullion is moved from one place to another within the vault to settle the international accounts. I think the ledgers are kept by the International Bank of Settlements in Geneva and the gold is transferred at storage vaults, one of which is at the New York Federal Reserve. .
Thanks Robert A Cook PE. They'll show us, huh? "We don't need your stinky old wealth, products, expertise, trade..."