This is no doubt a leadership challenge. Unfortunately, the issue becomes more complicated when the spouse is unwilling to cooperate.
Suspension of privileges over spouse safety concerns
The commander can revoke all kinds of privileges: pass, off post living, phone, personal property, alcohol, MWR, the list goes on. The key is to relate the revocation of privilege to the issue at hand. If there is danger in the home perhaps separating them for a period while they attend counseling would work. He could revoke pass, off post, phone, he could even issue a no-contact order other than at the time at counseling. If alcohol has been involved in the past he could revoke this privilege as well.
The command can also revoke or request revocation of spouse privileges including access to post facilities (PX/Commissary, MWR, Shopette, Church, etc.). If you are overseas the command can revoke command sponsorship and send the spouse home.
The command can order the Soldier to attend mandatory counseling. Consider anger management. They cannot order the wife to attend counseling, but based on the situation you describe she may be willing to attend.
I believe one of your goals should be to get both individuals assistance through the chaplain or other marriage counseling service. Another goal would be to get them to solve their problems between one another rather than bringing the problems to the chain of command. They will need to work through their problems if they plan to have a successful marriage. I am not suggesting the chain of command turn a blind eye because serious issue needs to be addressed. However, when spouses bring issues like these to the chain of command and then do not want to assist the chain of command the issue becomes complicated and usually begins to focus on the Soldier. The chain of command has to be cautious to ensure they are treating both individuals fairly.
Perhaps a prolonged separation with counseling will give them time to think and work the through the issue so they can become a mature and productive couple. The chain of command can then monitor interaction and rely on an expert counselor to provide information on when they should be allowed to return to living together. Once they are together again counseling should continue and the command should monitor the situation with input from the counselor. When it is resolved you can back away. If the problem resurfaces consider separation action. The key is to come up with a course of action that provides them assistance while at the same time making them responsible for settling the matter in a constructive way.
If there is proof of the threats, action can be taken under the UCMJ punitive articles for communicating a threat. If you are unable to resolve the issue through counseling, you can consider administrative separation of the Soldier for failing to handle personal affairs. AR 635-200 provides information on chapter separations.
You also mentioned domestic violence. Does this Soldier have access to personal weapons? Has the violence risen to the level of enforcing the Lautenberg amendment?
Any action your consider should be run through the local JAG and/or IG office to ensure you have their support and the plan does not violate anyone’s rights and is legally sufficient.