Just to say my thoughts are with you. I have the same problem DSO has an issue with the neighbours - only thing is some of the things my neighbours do are undreasonable some aren't DSO wants all sorted. I am also wary of conflict (for exactly the same reasons as you and for the same reasons DSO thinks I should be the one to sort it - cos I do that). I think all that you can do is promise that when the behaviour is an issue you will deal with that behaviour and that behaviour only all other times whist you understand that your wife finds it an issue you don't and therefore cannot deal with it (but she is free to do as she feels best about it). If she threatens to do somethign re the neighbour that you feel is unreasonable tell her that she is free to do so then if she is in the mood to listen tell her that although she is an adult and is free to do that you cannot support her in her actions because of xyz. If it is a truely unacceptable action (such as criminal damage) don't tellher not to but tell her that her behaviour is not acceptable.

Hang in there - you can't fix this for her and you shouldn't try.

P.