My wife?s brother treats her terribly and she tolerates it, although I cannot. What to do?

My wife (32F) and I (40M) have been married for about a year, and we have recurring arguments about this family dynamic. She?s an immigrant and comes from a conservative background, and she was raised with the idea that her older brother is always right and can exercise various kinds of authority over her. Now, as adults, he treats her incredibly poorly. In group settings, with family or friends, he often outright insults her, making derogatory comments about, mainly, her intelligence, judgment, and professional skills. As I watch her reaction to these comments, she clearly feels hurt and upset. But she never confronts him about it, and when we talk about it, she excuses his behavior, saying that in his mind, he?s ?just joking,? and this is how he was raised, he can?t help himself, etc.?so she tolerates it. And in addition to these insults, the brother and his wife have taken certain actions that have made my wife?s life significantly worse. I don?t want to give details in order to maintain anonymity, but think material life needs?money, safety, etc. Of course, the brother and his wife have never apologized for any of this, and again, my wife excuses it all, never confronting them about any of it.
I can?t stand to witness this. In my perception, the brother and his wife treat my wife terribly, really hurting her and making her life worse. I want to confront them and stand up for her. Or, at the very least, I want to stop seeing them. I can?t stand to go to family functions and try to smile and act cordial while burying that, in fact, I think they are awful. My wife, meanwhile, wants me to do exactly that. She doesn?t want conflict, she doesn?t want to change the dynamic, she just wants me to handle it the same way she does?tolerance. I feel like I can?t do that, like doing so is in conflict with my values about right and wrong. We have arguments about this repeatedly.
TL;DR - my wife?s brother treats her terribly and she excuses and tolerates it, and she wants me to do the same, but I feel that I can?t.
What to do?


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