One argument against the U.S. engaging in torture is that it degrades our “moral authority.” Unfortunately the concept of “moral authority” is quite dichotomous. To many in this world the U.S. has no right to claim moral authority, with or without torture (or drone strikes). It is unfortunate this is the framework of the discussion. The real issue should be human evolution/development. If we do not progress as a species, we run the risk of extinction, either through our own direct actions or through inadvertent ecological collapse.
The best argument against torture is that it does not move us forward as a species. It represents a backward step in our evolution/development. Instead of trying to be a “moral leader” the U.S. should strive to be the leader in promoting human evolution/development. What makes the system in the U.S. great is the degree to which it promotes life and dignity. The argument should be from a more objective scientific/humanistic standpoint rather than from the more subjective moral standpoint. This would avoid the dichotomous noise that comes from the arguments about whether the U.S. deserves to be regarded as a “moral leader.”