Somewhere--I forget where--we were supposed to have learned the lesson that committing crimes while in uniform because one is ordered to do so is not a moral OR a legal defense.

"The Nuremberg Defense is a legal defense that essentially states that the defendant was "only following orders" ("Befehl ist Befehl", literally "order is order") and is therefore not responsible for his crimes. The defense was most famously employed during the Nuremberg Trials, after which it is named.

Before the end of World War II, the Allies suspected such a defense might be employed, and issued the London Charter of the International Military Tribunal (IMT), which specifically stated that this was not a valid defense against charges of war crimes.

Thus, under Nuremberg Principle IV, "defense of superior orders" is not a defense for war crimes, although it might influence a sentencing authority to lessen the penalty. Nuremberg Principle IV states:

    "The fact that a person acted pursuant to order of his Government or of a superior does not relieve him from responsibility under international law, provided a moral choice was in fact possible to him."
"

WIkipedia on the Nuremberg Defense.