My 39F ex-husband 43M is being abused by his wife 44F and I?m tired of it.

TL;DR- My ex is being abused by his current wife and I?m about tired of it and don?t know what to do.
A bit of background. I?ve 39F known my ex 43M for 21 years. We got married stupid young (18 and 22) as is very common in the military lol. Seriously though, he was a great husband and we spent 13 good years together until his fourth and final combat tour. It really changed him. It was incredibly violent deployment and they lost a lot of guys. I have no shame in saying that I had a difficult time coping with the fallout and we both certainly didn?t have the tools to be a effective supportive partners for each other. He became an alcoholic overnight and I joined him because I was desperate to connect with him on any level. That obviously was not a sustainable way to live together and my kids needed one of us to be stable. We eventually ended our marriage amicably. We still remained best friends and co-parented well together until he met his current wife.
Simply put, I never stood a chance with her. It?s almost comical how completely opposite we are and I still wonder ?why her?!?? but that?s his business not mine. Everything about me from my looks, to my style, to my parenting, to my job, to my beliefs, and moral code were all offensive to her and she made it known. So she went on a mission to fix him. But fixing him looked like bringing him up to her standard. Everything about him started changing. His whole clothing style, his vehicle, his religious and political beliefs, and his parenting style. He even stopped being a fan of a sports team he loved because it was connected to me. She literally made him return a bag full of jerseys, shirts, basically anything team related. It blew me away.
Then it appeared that I was next on the list of things to change in his life. She wanted to completely erase my presence in his life. I got another return of stuff but this time it was all his copies of our family photos from our marriage, including baby and family history pictures. She was/is also adamant that he is to never speak to me alone. When we?d meet to trade off kids, she had to accompany him. If she couldn?t go she would send her older teen daughters, failing that she would track him on Life360 and start calling when his ?time was up? and we?re talking 5 mins. Our trade off time is usually when we would talk about kid stuff. Then, it escalated to fighting about me loud enough that our children heard. She would either badger him about still being in love with me or trying to character- assassinate and devalue me. Again, loud enough and often enough my kids would hear. They would come home upset because they hurt hearing awful things about me they knew to not be true. They also hated seeing their dad being beat down verbally. These fights would also escalate very loudly because my ex still drinks heavily and would lose his temper.
Now we are in this cycle where she will force him to call or text me over whatever she has decided she is upset about. She HAS TO witness him him do it and often coaches him in the background. He will try to dutifully put me in my place or be really cold and mean. He will say or demand things that I honestly used to get so angry and defensive about.
Here?s the kicker though!! Without fail, usually within an hour or so, he will sneak off and call me privately to explain. In those private conversations I see the man that?s I?ve always known. He?s calm, reasonable, apologetic, and almost always tells me what the real deal is. Then he and I will figure out how to resolve her issue so he can live more peacefully. Basically, she feels like she wins but nothing changes between him and I. Even our kids have adapted to this method. I realize this isn?t the best solution.
As sad as it is, he has to hide our friendship. They?ve had a few knock-down fights that he?s called me for advice on but had to pretend to go to the store to call me. He?s come over and gotten drunk with my long term partner and spilled his guts but again, he covered his tracks to hide it. She popped him in the face one night and he took off and ended up at the bar crying on the phone to me. My partner and I went to the bar and took care of him. Put him up in our guest room but not before we turned off his location services. All that to say, I?m never gonna give up on the guy but it gets hard to deal with sometimes.
I personally believe he?s being emotionally and financially abused at a minimum. When things get bad between them, she will threaten to get him fired, publicly humiliate him, make false claims, and she threatens to destroy him financially in divorce court. Knowing her, she would and could do it. She controls their finances completely. Her family is well connected at his job plus she?s really been able to manipulate him into a position where he will lose his everything. I know I need to stay available to him in case he decides to ever leave but after going through another cycle of disrupting my day with her grievances and his apology call have left me frustrated and tired.
I also want to say that I?m not completely innocent here. I am sure I?ve thrown attitude and said things BEFORE I figured this ****ing pattern out. All I ever wanted was to continue co-parenting as well as we all were before her arrival.
I don?t know what to do anymore. It is becoming very hard for me to keep myself in check. I have never ever let anyone talk to me and treat me so disrespectfully without getting the full weight of my response. She knows as well as I do that the only thing that saves her from me is my ex and my kids. I have about 3 more years until my youngest is 18. It?s going to be a long 3 years.
TL;DR- My ex is being abused by his current wife and I?m about tired of it and don?t know what to do.
EDIT- My question here is only about myself and my ex. My children are with me full time and always have been. They have weekend/holiday visitation with them. I have been sober since the divorce and my children both have therapists they are actively engaged with about this. This is strictly about the dynamic between him and I mostly.


Source.