Kickme, There is so much wisdom in 1000ships post. Working on and achieving detachment is so important, but I think it is even more important if the spouse still lives at home. Detachment is a protection for the LBS if it can be used as a shield. The faster the LBS gets it into their head that this crisis wasn't caused by something they did, said, didn't do, didn't say, etc. the easier it is to stop reacting to and start protecting themselves from the spew the MLCer throws out there.
Pain is the driving force that makes the MLCer lash out. It is emotional pain so intense that it can manifest into physical pain as well. As hurtful as it is for us LBSers to hear and witness what the MLCer dishes out it doesn't compare to what the MLCer is feeling. The saving component for us LBSers is that we, if we choose, can learn and understand what is happening to our S where they do not have the mental capacity at this time to realize why they are doing what they do. Until the MLCer looks inside themselves and resolves those internal issues they will not realize it is not the external things that are causing their misery, such as the spouse, children, responsibility or whatever they're blaming it on. Therefore, plain and simple, knowledge is indeed, power.
The bottom line in all this is that even if you were the perfect husband/wife, if your spouse is geared for a MLC there would be nothing you could have done to stop or prevent it. Delaying it maybe, but it will eventually catch up to them and they will enter into it with a vengeance.
Detachment is hard to achieve, but once you do it is a relief. It allows you to step back from the drama of the MLCer and begin the vital work on yourself. The most important thing is that you come out on the other side of your journey and know that you will be better than OK and able to handle whatever way your sitch turns out.