His overall point was, why does America have to play by a set of rules when our enemy doesn't?
In hopes that the next conflict does not have the same results; both sides resort to torture to get unreliable information.
If for some bizarre reason the U.S. invaded Canada, based on what I have seen on the media, I would fully expect to get tortured if I got captured. This is the legacy that the U.S. has to contend with for the future. You say that "we should set a moral standard" - it has been set, and I would rather die than be captured by the american military. Scary stuff going on in dark corners.
The reason for playing by the rules, or setting a
high moral standard is that it has an impact on any future engagement.