CNN chief international correspondent Christiane Amanpour just asked some expert whether there is anything that can be done to prevent such attacks.

Part of the answer – a part you won’t hear often – is this: When terrorists are captured they must be effectively interrogated in order to find out what they know about terrorist plots, cells and procedures.

No, that doesn’t mean torture. Yes, that does mean subjecting enemy combatants to “stress and duress,” using the most effective psychological methods to influence them to reveal what they know.

But if you do that, do not expect to be popular with the International Red Cross, Human Rights Watch, Amnesty International etc.