ISIS has a strategy of showing just how cruel and sub-humane they can be. Between cutting people’s heads off on a wholesale scale and burning people alive, there is some logic and a bit of psychology to it. And believe it or not it seems to be working.
The tactic of fear and terror is not new. It has been used by tribes and armies all throughout history. The psychology behind it is paralyze the enemy with fear making them impotent fighters.
The most obvious indication that this is working is most of the leaders of what could be defined as countries who actually care about their people, are very hesitant about facing ISIS face to face on the battle field. They will do standoff attacks with bombs from the sky, but they fear an enemy who will not take prisoners and kill everyone they capture.
That part is evident in all the hostages that were taken by ISIS were paraded in front of a camera and only done so to promote fear and terror in their enemies. Each and every one of them were killed in horrific ways despite some form of negotiation or communication. The message behind that is you will die if you face us. There will be no prisoners of war, only dead bodies.
Prisoners of war is perhaps the only single comforting thought a leader may have if he sends his people into war. So in this case, ISIS has removed that single comforting thought leaving only fear and terror.
That signal is also resonating with people who are affiliated with other terrorist organizations. Many of them are part of what has been called sleeper cells. They are just sitting around waiting for the word to blow up something. For the most part they are tired of sitting around pretending to be the people that they want to kill. So for them it makes sense to go and join ISIS as there is no waiting to do some damage and kill people.
In movies people that have Antisocial Personality Disorder act the same way. The Joker from the Batman movies is a good example. They are smart, intelligent, but have zero caring for other people. To them people are only to be used to further their own goals and killed if they get in the way or to promote more fear.
So yes there is a method behind ISIS making all this gruesomeness public. The longer they can produce fear and terror in their enemies, the more real estate falls under their control. That turns into more leverage as more innocent people fall under their influence and can be killed in their propaganda presentations. That in turn will have an after effect of political fallout for the hesitant leaders of other countries.
The bottom line is face to face confrontation on the battle field is the only way to stop ISIS. However the ISIS strategy of madness is effectively stopping the leaders who can stop them from taking that step.