Card Text - Forced: When this zone is attacked, the attacking player takes control of this card and moves it to a zone of his choice.
It has already been decided that it is allowed to move Spoils of War into your opponent's Battlefield after attacking a zone. My question is what happens when I'm attacking his Battlefield in a later turn - does 'move to a zone of (my) choice' include leaving it in the Battlefield, or does it have to go elsewhere. I'd say it's the latter, but I'd like to be sure.