Usually on the 2nd dui and those after people are forced to go to AA by spouses or authorities.
On the first dui most concerned for the alcoholic let the participation in AA slide, convinced we've now learned our lesson and not wanting to upset the alcoholic by issuing ultimatums about actually doing much of anything.
It really would be a waste of time to require him to attend now, as he'd likely do no more than suffer through a few meetings, which is of zero value.
Later on may make for better timing. Right now telling him you believe he can do it on his own and overlooking his dark moods and emotional swings is about all you can do in this situation. An alcoholic toughing it out can be difficult to be around. Just be glad you're not in his skin, as it's really very hard.
If it gets bad as time passes, he might consider seeing a therapist.