Defence against terrorists
I really don't see what the soldier has done wrong here. A kid using a slingshot stones him and he attempts to arrest the kid as the kid resists vehemently. Then a bunch of the kid's defenders show up and stop him from arresting the kid.
He then gives up the attempted arrest because he recognizes that catastrophic violence would be necessary to execute the arrest.
I don't see anything the soldier did wrong and there certainly wasn't any "brutalizing" going on.