Helping a dog with behavioral issues certainly includes teaching them obedience. But the difference is that learning those commands are not the end goal, they're simply a means to an end. In fact, dogs often already know the commands well but do them when they want to, not every time the owner asks.
The underlying issue for most behavioral issues is an unbalanced relationship between the dog and owner. The owner often suffers with the dog because he gave the dog love, freedom, and fun but not enough rules, guidance, and structure to help the dog know how to handle those privileges. Void of a leader that the dog can follow, he makes decisions on his own and unfortunately they're often the wrong decision: bark aggressively at things that seem threatening; make a stranger keep his distance by biting at the stranger's hand when they reach in to pet; rush the door every time the doorbell rings to warn the trespasser to stay out. While it sounds very simple -- the fact is it is in principle -- if the dog believes in the leadership of his human, he'll defer to the human's guidance on how to appropriately act in each of those situations.
The hard work, the diligence, the piece that pays off is insisting that the dog comply with the obedience command every time he hears it. The hard work is in follow through. It's in having an expectation for your dog's behavior and then helping him understand what that is (job one) and insisting that he do what he's capable of (job two). The hardest part about "job two" is that it lasts for the rest of your dog's life. But the easiest thing about job two is that the more you do it, the more engrained it becomes as a habit and the easier it is to do -- for both you and your dog. In essence, the work becomes so easy it feels more like rest. Good habits have that effect on dogs and people.