Britain could have to wait a decade for a free trade deal with the United States if it votes to leave the European Union, U.S. President Barack Obama said on Sunday in his final salvo of a disputed foray into British domestic politics. Obama has spent the last three days in London urging Britons to stay in the EU as the British public prepares to vote on whether to remain a member of the bloc on June 23. He played on the two countries' close historic ties to warn that from a U.S. perspective, leaving the EU would be a...