President Barack Obama, Defense Secretary Chuck Hagel and General Martin Dempsey, Chairman of the Joint Chiefs of Staff, bow their heads as Chaplain Col. Michael Brainerd delivers the invocation during a Memorial Day ceremony at the Arlington National Cemetery Memorial Amphitheater in Arlington, Va., May 26, 2014.

President Barack Obama, Defense Secretary Chuck Hagel and General Martin Dempsey, Chairman of the Joint Chiefs of Staff, bow their heads as Chaplain Col. Michael Brainerd delivers the invocation during a Memorial Day ceremony at the Arlington National Cemetery Memorial Amphitheater in Arlington, Va., May 26, 2014.