Julian Sanchez recently reminded us that the Japanese mis-judged the U.S.'s nuclear capabilities, at the end of WWII, based on false information they created via torture.
Paul Begala reminds us that we may have paid a huge price for torture, to the extent that the bogus interrogation of al-Libi was influential among the weak, like George "The Decider" Bush.
Even if the al-Libi data-point was 1% of "the case for war", that'd be a $2 billion dollar cost... On the other hand, if it was the last 1% required to convince someone, it wouldn't be wrong to allow the full $2 trillion dollar cost, so ...