depends on your view
If you want my honest answer...here it is...
If my husband were out of the picture and then came back home thinking everything was normal, I would have a problem with that. Especially if the cause of him being away from home was due to drug use. I am so happy that you are 18 months clean and that is a wonderful accomplishment, but have you reflected on the role that you wife had to jump into when you weren't clean? Not only did she have to be the caretaker of the children and probably for the most part, doing it all alone, she had to deal with the hurt and deceit that she was feeling but she had to keep going for herself and the children.
I am sure you realize, now, everything that has happend in both your lives, but you have to understand that once moms have control or are forced to have control, it is too hard to let go and let your guard down. I am sure your wife is dealing with way more than most people could imagine and if you ask me ...your recovery took how long?? I think you may need to double that time for her recovery. It is hard being hurt by a loved one and something that some people will get over in time and i bet there are some that never really get over it.
I think you two should sit down and talk and maybe ask her what is expected of you when it comes to the kids. I know my husband doesn't do much of the discipline in our family unless I give him that "LOOK".
Good luck and I hope all goes well.