I'm sure you can. And I can always offer some help even if I'm not directly involved.
[Michiru thinks for a few long moments]
At least in terms of the person who may not want to be part of truce, possibly having an addendum relating specifically to them if they choose not to be a part of it. Make it official to both sides and him that he will be acting on his own and the consequences resulting are his own issue and not that of the other side unless they help either in the planning or defense after he does something then it would be considered breaking the truce.