On Sunday EU regulations prohibiting dealings with Russian state energy companies came into effect. That should trigger a further decline in the volume of crude and refined products bought and traded by European companies, but it won’t bring flows to a halt.

Even when, or if, the EU finally imposes sanctions on the purchase of the country’s oil, it won’t stop Russian crude leaving Russian ports, nor the products made from it from fuelling European cars and trucks.

There are several reasons why...