Folks like to hate on capital gains tax. I think it's perceived as a rich-person deal. But homeowners, do they get taxed each year on the increase in value of their house? Almost the same thing, but not hated on the same way.
Yes? Their property tax goes up.
I realize that in society we don't typically care for these kinds of approaches, but how else do you actually deal with literal evil that sits safely on the other side of the globe, when their own governments won't do anything to stop it?
The problem is, in reality any such activity would largely be indistinguishable from terrorism.