to separate Iran’s Siamese twins seven years ago, described the failed operation in a speech last week in Lancaster, Pennsylvania. Carson said Ladan and Laleh Bijani, 29, insisted on being separated. “We were 90 percent done,” Carson said. “People were starting to celebrate. I wasn’t one of them.” They started to bleed, profusely. “And they died.” Carson, 59, said the lesson is that “not everything that we do is successful. We learn from mistakes.”