"Terrorist" has joined the ever-increasing group of shorthands for "evil". Along with "Nazi", "Fascist", "Communist", etc. That said, it's been used that way for quite a while. A rule of thumb about rebels: if they win (or the speaker wants them to), they're freedom fighters. If they lose (or the speaker doesn't wish them well), they're terrorists. If the speaker doesn't care, then they're just rebels. That's regardless of what their doctrine actually is. Oh, and if we're the ones using terror, it's "psychological warfare", not terrorism, because terrorism is bad. Somebody should, perhaps, take a dictionary to all those people...
If the object of the exercise is to create a situation where the region is put on a path to self-reinforcing stabilization (as opposed to a stabilization imposed by foreign armies), then measures based around degrading and disrespecting religious and cultural tenets of the people living there are absolutely counterproductive.
All you'd do is to send these people the very clear message that no, they are not respected, no, we will not stop disrespecting them, their culture, and their right to self-select their mode of government. This is not the right way to start a healing process.
Sure, the people fighting under the IS banner are criminals. Sure, they need to be stopped. But you can do that without trolling them into blind rage. What you are suggesting, that we give people who are already quite angry at western society over issues both real and imaginary more real issues to be angry about will not work. It'll just fuel more hatred.
As I said, it might work in the short term. But in the long term, people will remember this. They will tell their kids or students about it, and those will just become angry again, restarting the ****ing cycle. Beat them militarily, cut off their supply, but don't tell them that their culture is only worthy of disrespect.
Note that I'm not proposing just some blanket mass murder and desecrations, the way oppressive regimes sometimes tried crushing the populace. I am, in essence, proposing a punishment for being an IS member that would also extend into the afterlife. It should be definitely made clear that IS fighters are not respected, are not impressing anyone and are, in fact, committing crimes against both humanity and God (the very one they're "fighting for", which I why I'd expect it to be very damaging). The methods I proposed might not be the best choice (in practice, fooling about with pigs could be risky, as it could also raise questions about their handlers), but I'm sure Koran can provide some others. It might be as simple as refusing IS members their burial rites, on grounds on them being "unclean" simply by joining an evil organization. Rebels fighting against them likely already practice that on a small scale. It's about making it clear that they're not getting those heavenly virgins, but a lifetime of eternal torment.
Still, there is a big problem with the strategy I'm proposing - if executed by "outsiders", this runs the risk of being presented as fighting against Islam, as opposed to assaulting the IS specifically. Even if it was made explicit that desecration is used as a punishment for being an IS member, not because they're Muslims, it would be possible to twist it that way if it was done by a non-Islamic force. To be plausible, religious punishment might need to be exerted by people of a compatible religion. Otherwise, destruction of the very
idea of the Islamic State might not be assured, and it's survival is definitely an undesirable outcome. I don't think this invalidates the method in general, though. It's just something that needs to be considered for the implementation.
Remember, the IS isn't just some guerilla with legitimate grievances and questionable methods. They're fighting for domination of the entire region, and are using methods that are not only questionable, but clearly evil, no matter how you slice it. Their massacres can't even be justified as "necessary" to their ends, because they do them more harm than good. Not that they care, and they're not interested in what "Caliphate" was actually supposed to be, either. We need to do more than just destroy them militarily. The very idea of an entity like IS needs to be condemned and eredicated, like it happened with Nazism in Germany.
it's also hilariously ironic.
Intended effect. Good thing at least one person got the joke (yes, I do know this was not a good thing to say. Nobody's perfect).
