I’d say the sand nagger version of the Waffen SS is doing quite well and not being challenged—just like 1939, all over again.
ISIS likes headlines. ISIS doesn’t like a big fight. They attack when they can completely overwhelm by numbers and surprise. In Iraq, the ersatz national forces run and hide when ISIS arrives, but after months of planning they and the other Iranian proxy forces in the country counterattack and drive them out. Trouble is, they come back. It took months of fighting ISIS (and Turkey), but the Kurds ejected ISIS from the map flyspeck Kobane. ISIS fought hard, because losing was such bad PR. It’s never worked out to say that ISIS has peaked, so I won’t. But whatever new org arises from the latest ashes will doubtless make them look like a dramatization of a world war given by mimes.
And, just as in that conflict, the longer the world waits to really address the problem in a meaningful way (as in: when we have real leaders at the helm), it becomes bigger and will cost far more lives to bring it to an end.