"What, in your experience, has been the best way to deal with that?"

What a loaded question, lol.  Well, there is absolutely no simple answer and certainly not one that works for every situation, like most solutions to mental health issues.

I will tell you that there has been a goodly amount of dysfunction on both our parts for a lot of years, we are both very passive people and I have done more than my share of enabling inappropriate decision making.

It is only recently, in the clarifying light of a traumatic move to a new state and a recent crisis for DH that I have come to acknowledge that I personally cannot deal with that anymore.  That is the harsh truth.  So what I had to do was say so.  To say the words "I am not willing to just sit by until the Next Big Thing is past.". There will always be another Big Thing.  He and I learn to cope as a couple or I step away.

I agree with the above poster (sorry, can't see on my tablet, and forgot name!) about additional options other than passivity or aggression.  I would call the quoted "honesty" option by another name, assertiveness, for this is how I  learned it in the course of counselling.  But it seems, generally speaking, that the terms mean essentially the same thing, and the point being there are more options for confrontation than two.