Chairman's Handshake Marine Corps Gen. Joe Dunford, chairman of the Joint Chiefs of Staff, shakes hands with actor Adam Devine during a USO Holiday Tour stop aboard the USS Theodore Roosevelt in the Persian Gulf, Dec. 23, 2017. DoD photo by Navy Petty Officer 1st Class Dominique A. Pineiro SHARE IMAGE: Download Image: Full Size (1.02 MB) Photo By: Dominique A. Pineiro VIRIN: 171223-D-PB383-026.JPG Photo Gallery