I agree that BOTH partners need to go to counseling. Just one will not do the trick and will only result in GAL. But that is where people are committing a grave error I think. No effort should be held back in getting the spouse into counseling.
Lil's post on the Stockholm Syndrome talks about this. Recall how many people find it easier to placate the spouse (i.e., not push for joint counseling) in order to maintain peace in the home? But really they are just trying to protect themselves. The hard choice is to force the spouse into counseling any way possible, to set consequences if they don’t go. Few want to be this hard.