Carter Announces Nomination for Marine Corps Commandant Defense Secretary Ash Carter speaks while conducting a news conference with Army Gen. Martin E. Dempsey, left, chairman of the Joint Chiefs of Staff, at the Pentagon, July 1, 2015. During the event Carter announced the president’s nomination of Lt. Gen. Robert Neller, right center, as the next Marine Corps commandant. Neller would replace Gen. Joseph Dunford, right, who has been nominated to be the next chairman of the Joint Chiefs of Staff. SHARE: Download: Full Size (0.06 MB) Credit: VIRIN: 676497-U-QAO23-439.jpg Photo Gallery