Whether I choose to torture someone to save a child is one thing. If I chose to do that, then I chose to go to prison for it. So be it. Torture is reprehensible. If I commit the crime for whatever reason, then I should accept the penalty.
Its quite another thing to make torture sanctioned government policy. Welcome to Saddam's Iraq. Governments serve people, not torture them. And if a government official chooses to torture a subject to save lives, then let him raise it as a defence in court to mitigate his sentence.
Theo - the efficiency of torture is not relevant. The ethics of state-sanctioned torture is.