Details of a confrontation between two wild wolves

A confrontation was photographed and video-taped at close range between a wild alpha mate wolf (Canis lupus) of known history and an alien adult on Ellesmere Island, Northwest Territories, Canada. For 100-110 seconds the two stood near each other, maneuvered around, and snapped at each other until the alien fled. The alpha and his mate, who suddenly joined the encounter, chased the other wolf for 1.2 km and gave up without inflicting wounds. Discussed are possible reasons why this wolf was not killed, while other alien wolves have been.