Mattis Remarks Defense Secretary James N. Mattis explains to reporters how the engagements with NATO leaders create common ground and strengthen alliances as he travels to the alliance's headquarters in Brussels to meet with defense ministers.. DoD photo by Tech Sgt. Vernon Young Jr. SHARE: Download: Full Size (0.07 MB) Credit: Tech Sgt. Vernon Young Jr. VIRIN: 180606-D-IO684-001A.JPG Photo Gallery