Who's going to clamp down on the terrorists and force them to adhere to International law? Well, who?

How the hell can you enforce international laws by using tactics that break international laws?

The answer, if you can't figure it out for yourself is... you can't. Once the enforcers of laws break the very laws they are supposedly enforcing, there is no law. At that point there is only authoritarian rule by whoever is the strongest and most ruthless.

Hmmm... sounds a bit like Saddam's Iraq.

You can't protect people from something by becoming the thing you are supposedly protecting them against.