I would argue that terrorism is less abstract than murder. Also, the US "war on terror" is about terror that specifically relates or effects the US making it an even more specific classification.
It is not specific enough to end. Typically, wars end in either victory or defeat, but in the "war on terror" there is not even a clear definition of either.
Murder is far more concrete than the war on terror, because definitions of terrorist or what counts as a threat to national security is extremely nebulous and data about such determinations are hidden from most people, whereas murder is typically defined in laws that are generally accessible to the public and is strictly related to certain kinds of killings of human beings by other human beings.
