I think Katherine Steiner-Davion was responsible for Morgan's death. She was trying to take over the Federated Commonwealth and getting rid of Morgan would have prevented him from coming back solidly on Victor's side and it would make TF Serpent less effective increasing the chances that Victor would die in battle. She wouldn't really care if the destruction of the Smoke Jaguars succeeded because it wasn't on her side of the border and any failure would probably increase her chances at getting elected First Lord and discredit Victor.