when a Muslim or Christians does something like that here, we will react swiftly, sadly we can't do much more to force ISIS to do the same to their people (were already trying to destroy ISIS, what more can we do?)....
Explain the section in bold.
The major arms and money suppliers to the ISIS are the nations of Turkey, Saudi Arabia, Qatar and Kuwait. These countries are either NATO members themselves, or are having agreements with the NATO. If the US had any intention of destroying, or even weakening the ISIS, then it might have banned these countries from helping the ISIS.