Player Embed Code: <iframe width='500' height='300' scrolling='no' frameborder='0' style='border: none; overflow: hidden; width: 500px; height: 300px;' allowtransparency='true' src='https://www.dvidshub.net/video/embed/621630'></iframe> Download Embed Share Defense Secretary, Joint Chiefs Chairman Conduct Pentagon News Conference Defense.gov Aug. 28, 2018 | 1:24 Defense Secretary James N. Mattis and Marine Corps Gen. Joe Dunford, chairman of the Joint Chiefs of Staff, brief reporters at the Pentagon, Aug. 28, 2018.