There are a lot of arguments against waterboarding--it is immoral, it is unreliable, it encourages in-kind reprisals, etc.

But for those who are unconvined by these moral or strategic reasons, at least think about this from a self-preservation perspective.

According to Darius Rejali, a professor at Reed College in Oregon and author of a new book, Torture and Democracy:

Waterboarding reached the U.S. via a circuitous route. The Spanish exported the practice to the Philippines, which they colonized for centuries. It was then adapted by U.S. forces there at the start of the 20th century and, eventually, adopted by some police forces in the U.S. NPR article.

.... many decommissioned solders, when they came back to the United States brought with them knowledge of these techniques. When a soldier gets decommissioned end up becoming a policemen, many of these tortures appear then in the South especially as well as military prison lockups for conscientious objectors during World War I. [Second paragraph transcribed from All Things Considered 11/3/07]

One day, our tired and frustrated soldiers, national guardsmen, and Blackwater contractors will come home to become police officers, rent-a-cops, and crossing guards. Do we want them to have memories of having tortured another human being and the knowledge that our society, through our silence, sanctioned such torture? There are some lines you cannot uncross.