I think General Justin at General Joe's addressed this in one of his many dios... or maybe it was someone else... Something about one was his name and the other was an alias...It was a story where he was a double, triple or quadruple agent...

Turned from Cobra, joined Slaughter's, turned on the Joe's (or pretended to) and went back with intel (misinformation) to Cobra, then showed he was really a Joe in selfless act of sacrifice...Got badly injured, then grew a beard to cover the scars... Sorry if I messed that up or attributed the story to the wrong guy. I remember it was Justin, or a link from his site to another dio story...