The confusion about winning and losing should be cleared up before the horror of another attack, should it occur, further muddles our minds.
The terrorist proposition seems to be, "To get what we want, we intend to kill you, by any means possible" - to which an appropriate response would be "We better figure out what you want; meanwhile, we intend to prevent you killing us, by any means necessary." We may well be "preventing" for years until we can find a good response to what they want, but the latter part is simple: They win if they kill us; we win if we prevent them.
It is not the case that they win when we search and wiretap, etc., even in excess, as has been argued. Imagine this nonsense scenario:
Ahmad: "Osama, great news! The Augusta cell has been wiped out!"
Osama: "What's great about that?"
Ahmad: "The FBI illegally wiretapped everybody to find our martyrs!"
Osama: "We've won!"
It is at best absurd to think of the terrorists as obscene reformers of our system; at worst, such thinking may confuse the debate over how far to go in preventing attacks. Should "prevent, by any means necessary" be modified? Certainly, for we must not become monsters, although the debate must somehow respond to "kill, by any means possible."
Certainly we should go no further in abridging our liberties than we must, and no more ham-fisted disgraces as in Guantanamo Bay and Abu Ghraib. But the debate is ours; Osama has no dog in that fight. It is true that we abridge to prevent being killed, but it is false that they kill to compel us to abridge. The dangerous and silly sophistry that they win when we abridge must be exposed and expunged.