The healthy communication between humans and dogs and has to do with reading the mind of the other with language. It is a two way communication: the human is talking to his dog, and the other way around. An example would be, that the human is reading a book aloud in front of the dog, to indoctrinate his mind with the right ideas, but the opposite direction is also important. Every dogs is sending out signals and it is up to the human to interpret them.
The most important question is maybe: why are dogs so aggressive? Answering this is easy, because they are defending limited resources. A god usually lives together with other animals in the wild life and he needs some goods: a place to sleep, something to eat, a position in the hierarchy and so on. All of these resources are confined, that means they are not infinitely. If dog1 is eating the fish, dog2 can't eat the same fish. The result is a conflict about who owns the meal. And a conflict is solved with aggression. And that is the reason why dogs have invented lots of aggressive behaviors and signs to warn, inform and fight with other dogs.
To provoke aggressive behavior at dogs the easiest thing to do is to limit the given ressources. For example to take away a fish from the dog, to reduce the amount of space he has, to disturb his play. From an abstract point of view this is equal to make the limit of the ressources obvious. As a consequence the dog takes a decision, in most cases he decides to fight for his ressources. If he is a wild dog this is equal to an immediate attack, if the dog was trained by human he can decide for a non-aggressive behavior for example he can beg. That means, he is asking polity if he can get the fish back, if he can get his space back and so on.
Begging for food is a very usual behavior. It is a learned behavior which transforms formally aggressive fight over low resources into a social accepted behavior with the same aim: to get in control of the limited food. Perhaps, dogs are so fascinating for humans, because human are using the same technique. Like dogs, they have the major problem that food, space, and social hierarchy are limited ressources so they have invented strategies to get in control of them.
To make the point clear: The precondition for any dog behavior are resources. If no conflict about limited amount of food, space or hierarchy is there the dog will do nothing. He is bored and ignores the situation. That means, if nobody has stolen his fish then there is no problem. Perhaps the dog is memorizing about previous experiences from last week to improve his behavior in the future, but in most cases he has forgotten the episode. That is the difference between dogs and humans. Humans can make notes on their laptop, that is outside of the scope of animals.
What I want to explain is, that dogs itself are not aggressive. They have no brain which controls their behavior. Their behavior has always to do with games they play. The situation is located outside of the dog, for example if dog1 is catching the food of dog2. This game is about: two players, a limited ressources and a social hierarchy. And it is up to the individual to play the game. And this results into a certain behavior.
So called Alpha dogs have developed strategies for getting the most ressources. Either they are super-aggressive or they are super-cute. In both cases they get the most of the high-values ressources, which means free space, high quality food, social hierarchy, fresh water and so on. What the dogs are talking to each other is how to develop such strategies. And if they have acquired a behavior they will use it in reality.