It is a certainty Muslims in the middle east will continue to turn their US supplied weapons on Americans in their countries. I've seen the absolute slaughter the US has done to many innocent people over there, and Revenge is a universal absolute. I support the revenge tool because it's a good deterrent.
I don't worry about the very few terrorist attacks on US soil, I still have a better chance of being struck by lighting. And besides, so called Al-Qaeda terrorists don't own fighter jets or even a row boat.