i think, maybe, the reason it is being worded as a "war on terror" is because of a few reasons...
one. it *really* began as a reaction to a terrorist action. yes, things may have been going on before hand, but you didnt hear about it like afterwards.
two. it is not a war on a specific country or a specific group of people. in reality, it may appear to be, but i dont remember the US declaring war on islamics. probably because they didnt. if japan bombed pearl harbor (hypothetically speaking...) we might declare war on japan. we might also become suspicious of japanese people in the US, but we would declare war on a specific country. if a particular group of people moved into your country, lived in your neighborhood, bought groceries at the safeway down the street, and then proceeded to aid in attacking your country, you might, likewise, become suspicious of other people similar to them. unfortunate, but true. but since they were not acting on behalf of a country, we can not declare war on a country. we also can not attack their religion. its their actions, not their religion that are being fought. there wasnt a "war on islam" before, and theres not one now, because "islam" didnt attack, terrorists did.
three. while, no, we are not fighting ALL terrorists now, this particular threat is the most dangerous at the moment. i think that it is hoped that if they are defeated, other terrorist groups will back off.
four. i will repeat myself some... we are not going after people because they worship a particular diety. we are going after them because they killed people. other innocent people will die in the process, but it IS a war...
i am not very good at putting thoughts into words, so appologies for sounding like an idiot.