Why did proponents of the torture memo believe that waterboarding was an acceptable interrogation technique?

Proponents of the torture memo believed that waterboarding was an acceptable interrogation technique because they argued it did not constitute torture under U.S. law and international conventions. They claimed it was a controlled and reversible method that could yield valuable intelligence while minimizing long-term physical harm. Additionally, some officials viewed the urgency of preventing terrorist attacks as a justification for employing aggressive interrogation techniques. This perspective was rooted in a broader interpretation of national security needs during the post-9/11 era.