WELCOME CEREMONY U.S. Army Gen. Martin E. Dempsey, left, chairman of the Joint Chiefs of Staff, stands at attention with Canadian Air Force Gen. Thomas J. Lawson, chief of Canada's defense staff, during a welcome ceremony in Ottawa, Ontario, April 15, 2014. SHARE: Download: Full Size (0.06 MB) Credit: VIRIN: 008206-S-ZAK30-812.jpg Photo Gallery