Okay, so let me get this straight.
1. The President appoints the Attorney General, who is in charge of the Justice Department and is the de facto top lawyer in the land.
2. The AG issues an opinion giving the President the green light on some action—like, say, torturing foreign nationals whom we have imprisoned without charge.
3. Word of the President's actions gets out, and Justice is asked to open an investigation into what is widely perceived to be a war crime.
4. No can do, says the AG, as we already told the White House they could do it.
Did I mention that the President is the Attorney General's boss???
So, we've come a long way from Nixon's "If the President does it, it's legal" to today's statement that if the President does it and the Attorney General says it's okay, then it's legal. Wow.
And apparently we have completely forgotten a series of post-War events in a German city called Nuremberg, as well as civilian prosecutions and military courts-martial for other Americans who have used waterboarding as an interrogation/torture technique.
How silly of me. I thought the word "justice" in "Department of Justice" actually meant, well… justice.