Each of the various methods of interrogation works under some circumstances and fails under others. I doubt anybody has done a scientific, double-blind comparative study in urder to partial out the degree to which the various methods maybe relied upon, the conditions, the outcomes and the peril related to the information sought.

For example, If I was reasonably certain that you (anybody) knew where a molester-torturer-murderer was holding a captive child I believe I would forget the constitutional protections normally afforded you and the suspect.

But if you were a suspect in an armed robbery of a liquor store I hope I would have the good sense to treat you with full constitutional protection.

In the first instance, an immanent, terrible fate awaits an innocent victim. Time is important. In the second instance an insurance company and a convenience store are on the hook for material losses, which I see as a far lesser crime and with no serious time constraint.

I think we can imagine a rich spectrum of possibilities, some of which exceed the first example (say, Kirk Vining has an H-Bomb in his closet), but most are probably far less an immanent threat to life and property.

In general, I agree with Alan Dershowitz, that full constitutional protections should be extended to all people of the planet. But we should also recognize that some extraordinary circumstances are so dire and the outcomes so burdensome, that we should recognize a moral rather than legal guidance.

I suspect this line of argument is what supports Obama's drone strikes on American citizens not formally charged with a crime and beyond the normal judicial review.

If you have a diamond-sharp belief knowing all-encompassing answer, well good on you. I don't.