This isnt what we're asking for, though. We were discussing in the other thread the possibility of a popup when attacked that lets you pick one of your own valid claims against your attacker, if you have any. Unless the Muslim attacker had a valid claim on Bohemia, he couldn't take it in a defensive war with such a system.
Well he's a Muslim... I imagine he has a holy war CB on everything the vassal owns...
One thing though, do you not get to imprison your opponent after winning a defensive war? (I haven't actually fought one outside my own realm yet). People talking about wanting reparations kind of hints that you can't, but that would give you some cash if you wanted it, and the ability to execute, without (as far as I can see) leading to problems.