Trump threatens 50% tariffs. How might Europe strike back?

The truce did not last long. On May 23rd President Donald Trump threatened to impose a tariff of 50% on imports from the European Union, more than double the size of his earlier threat of 20%. "Our discussions with them are going nowhere,” he said. The bloc is "very difficult to deal with”. Without progress, the levy will come into effect on June 1st. Markets swooned once again in response. But Mr Trump's announcement was a particular blow to European officials, who had been feeling cautiously optimistic. According to an internal memo from May 14th, seen by The Economist, they…