Submarine Tour Marine Corps Gen. Joe Dunford, chairman of the Joint Chiefs of Staff, tours the nuclear-fleet submarine HMS Ambush during a visit to Scotland, Aug. 25, 2017. DoD photo by Petty Officer 1st Class Dominque A. Pineiro SHARE: Download: Full Size (1.55 MB) Tags: Chairman, u.k., Dunford Credit: Petty Officer 1st Class Dominque A. Pineiro VIRIN: 170826-D-PB383-049.JPG Photo Gallery