Public Choice Theory accounts for the behaviour of politicians, bureaucrats and state institutions as if they acted in their own self-interest. Stated like that it seems obvious, but it is surprising the number of people - especially media pundits - who believe in the essential neutrality or even benevolence of institutions.
Everyone who has not had their brain curdled by political correctness knows that torture frequently works, provided you ask the right questions and check the answers for accuracy. We therefore don't abhor torture for utilitarian reasons, but for reasons of public choice theory.
In the many countries where torture is routine, the police and security services use torture to get easy convictions, frame political opponents and terrorise dissenters.
None of this is in the public interest, and the only way to avoid such outcomes is to delegitimise torture altogether. We all know that torture will still occur where the absolute need to get information trumps the political costs of keeping its use absolutely covert.
There, what was so intellectually difficult about that?