President Obama nominated Army Gen. Martin E. Dempsey as chairman of the Joint Chiefs of Staff and promoted two other senior military leaders Monday, completing an overhaul of his national security team in advance of his reelection campaign…

Obama said Dempsey and Winnefeld would make “an extraordinary team” on the Joint Chiefs of Staff. “Between them they bring deep experience in virtually every domain,” he said. “Land, air, space, sea and cyber.“