If there were a set of accords about the rules of marital warfare, the silent treatment would surely be banned. Effective as it can be (the part of the brain that perceives social connection also perceives pain and threat, which is why being iced out by a loved one hurts so much and makes us long to reconnect) it’s a petty and passive aggressive tactic, one that breaks every rule of healthy communication. One way to respond when it’s used against you? Comment on the silence. Say, “I notice you’re shutting down and not responding to me."  Then, use more ‘I’ statements to explain how their silence makes you feel, and how it’s difficult to figure out the underlying issue. Once it’s over, talk at a later time about ways to prevent the reaction. And maybe create your own accords to make arguments a bit less frustrating. Treaties optional.