The U.K. left the EU on Jan. 31, 2020. The application of temporary trading and customs measures through Dec. 31, 2020 has prevented the bulk of potential customs and trade disruptions so far. Yet, there are already clear signs of the challenges yet to come. Whether or not a new customs and trade deal is agreed between the EC and U.K. by year end may be immaterial given the minimal time for ratification and entry into force. The most recent challenge has come from several European countries having closed their borders with the U.K. due to the established emergence of a more transmissible...