male to male aggression

Question
Dear Jill,
I have a 2 German Shepherds. Both are entire males, both are used at stud. So far, I have had not much problem with aggression between them, especially after recognizing that i must support the dog that is the most dominant between the two. My problem exists with my dominant dog with other male dogs. However, when approaching any strange dog, he is confrontational, trotting up to them, hair up, and tail raised very high and lots of whining. Then when I approach he begins to growl. He has not attacked a dog..yet. but displays his threats...I am concerned that the closer my proximity, the more aggressive he becomes with the other dogs, particularly males. My subordinate male is quite the opposite, being of a more generous and much calmer nature.
I accept I may well be the problem and that I maybe doing or not doing something that is making it all worse. These boys had plenty of puppy socialization, are obedience trained, the aggressive dog particularly enjoys his obedience work, regularly use their noses in searching activities and get walked twice a day. The only other thing I can say about this dog is that we were attacked by a large male rottweiller when he was 12 weeks old.. I HAD to pick him up to prevent mortal damage. Please note, he does not display aggression towards me or other people. Please help..I have had differing advice from a number of dog trainers..and nothing seems to really help...only make it worse...I need to know if its me and what am I doing wrong and how to resolve it.

Answer
It's obvious from your description that YOU are the common denominator in this dominance display.  It's VERY COMMON for an owner to REACT when his/her dog displays any sort of potentially dangerous behavior.  Even the most MINIMAL physical reaction (a shift of your eye is enough, not to mention the adrenaline which is flowing from your breath) will exaggerate the dog's need to display control (ESPECIALLY a breed like the GSD.)  You need an objective observer to watch one of these interactions and to especially observe YOU.  I suggest you get rid of the dog trainers and find a real professional in animal behavior.  If you are the culprit, there are simple behaviors you can change (including walking AWAY from the dog VERY QUICKLY and observing his redirection.)  A dog that is dependent upon your unconscious contribution will immediately LOOK FOR YOU and might show strong displacement behaviors (sniffing the ground, looking around aimlessly) which are clear indicators that you are the problem.

Additionally, breeding requires strong husbandry; one must be certain that there are NO temperament flaws in one's breeding stock.  This dog is demonstrating a fear dominance aggression problem and should immediately be removed from breeding.