Human T-lymphotropic virus. The human T-lymphotropic virus or human T-cell lymphotropic virus (HTLV) family of viruses are a group of human retroviruses that are known to cause a type of cancer called adult T-cell leukemia/lymphoma and a demyelinating disease called HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP).
The Geneva convention doesn't apply to ISIS anyways as they are considered unlawful combatants. We ran into these gray area issues in Iraq as many of the insurgents were not locals, non-uniformed and not state sponsored.
The reason ISIS is not attacking Israel is it only has so much band width of terror and it knows that if it sends one rocket or suicide bomber into Israel, the reaction will be a reign of terror on the IS like it has never seen. BTW with or without the US or UN approval.