If governments truly valued the lives of the governed, they would do whatever it takes to protect the lives of their people. Damn the media and the international community. If that means terminating entire bloodlines, nuking your enemy, then so be it. As long as we play by their rules, or even by rule of international law, we will probably fail in the long run.
You must put the fear of God in these people. They kill one of yours, you kill 1,000 of them. You kill their mother, fathers, brothers, everyone in their family like the Mafia used to do. You make the price of their folly unbearable.
You know those children studying to be terrorists in Pakistan? Can you rehabilitate them? Try, but if you cannot, kill them. Life is harsh.