Terrorism as far as we can see is basically incredibly ineffective for inspiring any sort of changes, and serves to enrage your enemy, much like indiscriminate mass bombing often strengthen the resolve of those who are on the receiving end of it.
If only a few of those hanging chads in Florida had hung differently, or if Gore had further pressed the issue...
I think that deserves a qualification: terrorism can be very effective against an occupying force and when it has the backing of the local population. But terrorism in its 20th century sense of "propaganda of the deed" has indeed shown very ineffective time and again.
I recall an anarchist revolutionary in the early 20th century assassinating a factory owner or somesuch thinking that his act of violence would spur the combative union workers into revolutionary action only to find out that they would turn on him instead. On the other hand there are plenty of documented successes at guerilla warfare - of course always contingent on wide support from the local civilians they were trying to liberate. Likewise, the bombing campaigns in WW2 did little to break the spirit of the civilian population and at worst only radicalized them.
What else can you use to stop terrorism? You can prevent it from happening in the first place. 9/11 and the Hamas terror attacks could of been prevented. Future terror attacks can be prevented too. War is reactionary and somehow hasn't stopped terrorism despite its blunt usage. And terrorism hasn't stopped bombs from falling yet either.