That's what torture does: it creates a miasma of unknowing, about as dangerous a situation in wartime as one can imagine. This hideous fate was made … - Andrew Sullivan

Monsters remain human beings. In fact, to reduce them to a subhuman level is to exonerate them of their acts of terrorism and mass murder — just as animals are not deemed morally responsible for killing. Insisting on the humanity of terrorists is, in fact, critical to maintaining their profound responsibility for the evil they commit.
And, if they are human, then they must necessarily not be treated in an inhuman fashion. You cannot lower the moral baseline of a terrorist to the subhuman without betraying a fundamental value.

If you suspend the Geneva Conventions, give the green light to anything that will get intelligence, round up thousands all over the globe with reckless disregard for guilt or innocence, you are effectively and knowingly issuing orders to seize innocent people and torture them. Any president who decides to do that and then says it was not his intention to do that is a fraud or a fool.

At home, the public has come to accept torture as a legitimate instrument of government, something that the Founding Fathers would have been aghast at. We have come to accept that the president is not bound by habeas corpus, if he decides he isn't. He can sign laws and say they don't apply to him. We know that an American citizen can be detained for years without charges and tortured and abused — and then critical evidence of his torture will be "lost." We have come to accept our phones being tapped without a warrant and without our even knowing about it. These huge surrenders of liberty have occurred without much public outcry. When the next major terrorist attack comes, the question will simply be how much liberty Americans have left. That is a victory al Qaeda could not have achieved by force of arms. It is something they have achieved with our witting and conscious help.