CNN’s latest revival of the 1980s classic “Crossfire” lasted only nine minutes, but it was excellent television. On the left was the network’s own chief international correspondent, Christiane Amanpour; on the right, Daniel Hannan, a British member of the European Parliament and a leader in the successful Brexit referendum campaign.

It was a lively drama, with both participants giving as good as they got. Hannan had the better of the argument, mostly because Amanpour was too transparent in her dishonesty. She kept accusing...