Islamic Family

Boycotted Uncle

Respected Scholar, Assalam aleykumtwo of my uncles and their wives are neighbours since many years (both have rented houses) and often have arguments regarding petty issues. But recently one of my aunt verbally abused the other aunt very badly and unfortunately her husband has completely ignored her fault and instead he's supporting her. My father is the eldest brother and most of the times he resolves the disputes among brothers and sisters. This time too, my uncle and aunt approached him to settle the dispute and asked for an apology from the other uncle and aunt for their extremely bad behaviour. My father tried to reconcile the matter and advised (with all his other brothers and sisters approval and support) his brother whose wife abused the other aunt to leave the neighbourhood and rent another house but his brother doesn't recognize his authority over him and refused to obey him. My father, failing to see any solution for the problem between his brothers, for the sake of making his brother accept his proposal, advised all other brothers and sisters of his to boycott him till he shifts his house. Now all have stopped going to his place (they didn't sever the ties, they just avoided going to his house). Now my uncle is accusing my father that he broke him off f rom all his brothers and sisters (even though all his other brothers and sisters were participants in making this decision) and accusing him that he's doing khata rahmi. Indeed my father invited them once in his son's engagement ceremony and though they attended it, they misbehaved in front of the guests and didn't have food in the ceremony. After a while, again there was a ceremony and my parents were afraid that if they invite them, they might misbehave again, so my father called him beforehand and tried to explain him not to misbehave again, but my uncle took it negatively and again accused him saying that actually he didn't want to invite them with this excuse. Now the situation went out of my father's hands, all brothers and sisters are innocent in my uncle's eyes, except my father, as he authorized the decision of boycotting him. And after this incident, my uncle has completely severed the ties with my father and they aren't communicating anymore. I'm not sure if my father is at fault of breaking the ties as he authorized the decision to boycott him. I can't understand, Islamically, who's at fault. If my father is at fault then what would you suggest him to do? And how can i suggest it to him without appearing disrespectful? Kindly help.I apologize for such a long question.thank you.