I found the model of alcoholism as a disease to be really useful, once I got my head around it.
I read the book 'Under the Influence'. It explains how my STBXAH could become an alcoholic when others round him didn't. He cannot help being an alcoholic. What he can change, though, is how he handles his disease.
This is where personal responsibility comes into it for me. Alcoholism is a disease, not an excuse! I only hold my STBXAH accountable for his behaviour, not for being an alcoholic. Its a fine distinction I know, but it helps me focus on the problems in our relationship - alcoholism in and of itself may be the red herring there!!
Does this make sense?