It should not be legal for the US Government to extra-judicially kidnap, torture, and execute US citizens or others who have never been charged with a crime, never mind convicted, no matter how bad they are suspected to be.
I don't care if you use newspeak terms like "rendition" instead of kidnap and "water board" instead of water torture like it was called during the Spanish Inquisition, or when it was Pol Pot's favorite torture, or when it was used by the Nazis, or when we prosecuted a Japanese torturer for doing it to US soldiers. It's wrong, it's illegal, and it's not something the "good guys" should be doing.
Follow the Constitution.
Follow the law.
Prosecute those who authorized it.