Torture is good for two things: intimidation and extracting false confessions. As an intelligence-gathering mechanism, it’s much worse than worthless. You get no good intelligence, while what you do get is decidedly bad, including a corrosion of the legitimacy of security agencies and a weakening of the foundation of liberal democracy itself.
To be sure, a national government’s primary responsibility is to serve the interests of its own people. And national interests — say, in security and material prosperity — can be morally legitimate. But the pursuit of those interests to the exclusion of all other considerations would amount to the kind of ruthless nationalist realpolitik that Vladimir Putin is now playing so successfully.
Americans are already too inclined to believe in their own righteousness. Their tendency toward what Alexis de Tocqueville called ‘the perpetual utterance of self-applause’ often leads them to make foolish mistakes. They certainly don’t need theologians telling them that their good intentions entitle them, over the inevitable objections of billions of their would-be subjects, to appoint themselves the world’s benevolent despot.