Macron returns to the Sorbonne to warn of Europe's mortality

French president Emmanuel Macron delivers a speech on Europe in at the Sorbonne University in Paris on Thursday. Photograph: Christophe Petit Tesson/AFP via Getty Images Six years after giving his first landmark speech on the future of Europe, Emmanuel Macron returned to the Sorbonne University's amphitheatre this week for another set piece. But against the same stunning backdrop, the French president was speaking in a much-changed Europe. Months after he was first elected in 2017, he set out an optimistic vision for the reform of the European Union. Now the tone was darker, with Macron sending grave warnings about the…