Torture is necessary to ensure national security.

People will often make the argument that you have to allow it in certain instances--for example, where there's a ticking time-bomb somewhere and you have to get the terrorist to tell you where. But is that really persuasive? It assumes that torturing will get you the answer, or get the answer more quickly than regular interrogation. I'm not so sure that it works that way--and given the extreme downside to our civil liberties I don't really see why anyone would say that we have to allow for torture in certain cases.