“It wasn’t just our understanding and tolerance. It was the combination of his and ours and the dogs’.”
Wolves are extremely intuitive creatures, meaning they are capable of knowing how people are feeling at any given time. Nick believed that it was as if he could read that he wanted to live in a friendly environment, without the worry of common hostility or violence taking place. He likely sensed this from Nick’s pooch, as well.
If Romeo wasn’t feeling threatened by anything in the house, he would have no other reason to lash out against them. This would create a stable living environment for the new family and best of all, no one would have to live in fear.