Interrogating prisoners is something of an art. Coercion, whether the 3rd degree methods of modern police to real old fashioned medieval torture, is a deal between the interrogators and the subject. Talk and it will stop hurting. Most subjects understand this. And, most subjects want it to stop hurting, and so they talk. They will lie their heads off and say anything the interrogators want them to say.
For criminal police work, where all they have to do is make the subject say " I confess" this probably works. For military intelligence work where we want the location of enemy troops, supplies, other assets, or operational plans, or names of leaders and agents, targets for airstrikes, success of past attacks, or size of military units, it's not so effective. The subject, under duress, will invent answers to the questions. This defeats the purpose of interrogation, by filling the intelligence files with nonsense.
So I am not in sympathy with president Trump's call to waterboard more subjects. I don't think you get useful intelligence this way. CIA used to have some pretty good interrogators. They got Khalid Sheik Mohammad to sing like a canary. Then came the great CIA shakeup over black sites, waterboarding, VHS tapes of interrogation. I wonder if CIA has anyone left who can interrogate effectively. Or would dare to do so from fear of prosecution.
What we ought to do is take more prisoners. Obama liked killing 'em rather than taking 'em alive, probably to try to empty out Gitmo. Seal Team Six had Bin Laden at their mercy, they had plenty of airlift, they should have cuffed him and flown him out. Rather than calling in an airstrike, send troops in by helicopter to capture alive as many as possible. Take the prisoners to Gitmo and grill 'em medium rare. Do fancy televised trials for the higher ups like Bin Laden.