This goes both ways. When I (a man) was the target of some really pretty severe domestic violence (I was threatened with a knife, attacked with blunt objects a

This goes both ways. When I (a man) was the target of some really pretty severe domestic violence (I was threatened with a knife, attacked with blunt objects and more several times a week), the reason why I eventually decided (quite deliberatively) to respond with physical force was that I looked at what my options were in the legal system and realized I didn't have any, that if I called the cops, they'd probably arrest me, not her. So I hit back with very measured force (except one time she hit me from behind with a blunt object and I hit back with full force once out of fear she might have knife in her other hand). Given the scale of what I was going through I don't think anyone would claim it wasn't self-defence. So these things to some extent perpetuate eachother.