I am not a lawyer, and I have certainly never played one on television, but it does not take a juris doctor to see that the US will expect more than a document saying, “Yep, I abided by the price cap”, to ensure compliance with its sanctions on Russia.

That was in stark relief this week as the US Department of the Treasury’s Office of Foreign Asset Control reportedly sent out letters to a swathe of tanker industry companies seeking information on Russian oil shipments.