easier to pull back from an alcoholic and make them responsible for their actions (i.e. cleaning up their own puke, dealing with the law etc.) but what will detaching do to make him responsible for his actions. Do I just withdraw and not do anything to try and save this M?
You don't have to "make him responsible"; he already IS responsible. You just have to recognize that and cease trying to make him something he already is. He is responsible for his actions whether either or both of your recognize it and act accordingly.
If you truly recognized that he is responsible for himself, who he is, what he does, would that change your behavior at all? Ponder for a moment (while I ponder, too).
Should you withdraw? I don't know... How can you save a marriage by yourself?
If saving the marriage is all you want to do, you can do that by letting him be. Your marriage, as it is, is-- presto!-- saved.
If THIS is not the marriage you want (and I fully comprehend, believe me, that it is not) and he will not join you in remodeling the marriage... what indeed are your options?