Three new rules came into effect this month designed to put pressure on Russian oil exports - the main upshot to date has been to create a tanker logjam around the Bosporus and the Dardanelles. The $60 Russian oil price cap and the European ban on Russian seaborne crude kicked in on December 5, but it was Turkey’s decision to check that tankers transiting tankers transiting Turkish waters are carrying insurance letters which caused the greatest problems so far. The International Group of P&...