Suppose we close Guantanamo and everybody there, including the probably large number that had no interest in terrorism before their imprisonment, decides to become a terrorist as soon as they get out. This could still be a positive development against terrorism, if Obama's magnanimous gesture and our return to respectability prevented even more people from getting consumed with hatred of America and becoming terrorists.
The total population of terrorists ebbs and flows all the time. When the number goes up by one hundred, no one much notices. If the number goes up by one hundred because we release some previously identified terrorists, there is or will be a public outcry. But it's the same consequence...
We evaluate outcomes differently when we feel we are in control or should be in control. We should examine this intuition carefully, since it is not always justified.
Not driving people crazy with egregious civil liberties violations should be a larger part of our anti-terrorism arsenal. I'd like to see us try it a little more.