Forget know your customer. With the US ramping up its use of trade and economic sanctions to implement its foreign policy agenda, the leader of the US Treasury office that enforces those sanctions wants financial firms to know not only their customer, but their customer’s customer’s customer.

As Adam Szubin, director of the Office of Foreign Assets Control, puts it: "Even if the transaction is here for a millisecond, you're transacting here in the US." And that means banks and brokers handling every part of those transactions need to know who they are dealing with.