“You can’t,” the official said, and with just six weeks until the next wave of U.S. sanctions hits Iran on Nov. 4, European diplomats acknowledge he was right. The European Union has failed to design a workable legal shield for its companies in Iran to beat the global reach of the U.S. financial system and defy President Trump, the diplomats say. EU-Iranian trade this year is running at 2 billion euros ($2.35 billion) a month, but this is expected to fall as big European companies pull out and Iranian oil exports are choked off by U.S. sanctions.