Probably the best way to make honor matter is to change the mechanics to favor growing while warring.
A major issue with warring is the power of holding the button being so overwhelming, which encourages a lot of stalling and positioning in order to declare wars. One partial solution to that would be to fade in wartime GBP, so that it takes 24 hours before deep chaining is fully possible, and fear of giving a button away without having an overwhelming advantage is reduced. But that is only a small part of the problem with relations at present.