Project Gauntlet Series by Richard Turner

A sudden and brutal attack on a coalition training camp in Iraq wipes out all but two survivors: Captain James Grant and Australian SAS Sergeant David Maclean. Drawn into a clandestine world that deals with unusual encounters the two soldiers volunteer to help with the investigation into an alleged UFO crash in Alaska. The mission, however, is far from simple as it soon becomes apparent that something dangerous is going on and not everyone is as they appear to be.