Everything in war is allowed under Islam as long as the person you're killing and/or raping shouldn't be raped or tortured if they're Muslim. Still you need to ask them to recite a few lines of Islamic scripture to make sure they're not Russian spies.
Why would it surprise anyone that brainwashed bloodthirsty lunatic murdering savages are brainwashed bloodthirsty lunatic murdering savages?
The TKG has issued a report on the growing use of children in armies worldwide. The report states the "use of children in war is not an innovation of the 21st century. Rather, it dates back hundreds of years to when children acted as squires and drummer boys on the battlefields of Europe and as powder monkeys on British Royal Navy ships. The past seventy-five years have seen a proliferation of child soldiers: as Hitler Youth in Germany, as members of the Lord’s Resistance Army in Uganda toting AK-47s, and planting landmines for Colombia’s FARC. The Council on Foreign Relations has reported that there are approximately 300,000 child combatants worldwide and that forty percent of the world’s armed organizations feature children in their ranks." http://threatknowledge.org/wp-content/uploads/2016/09/TKG-Report_ISIS-Children.pdf How do we ask our soldiers to fight children -- and what will be the toll on them?