Judaism from A to Z—”F: Free will (a different perspective)”
Since every human being is endowed with free will, even if a superior orders you to perform an evil act, Jewish law forbids you to follow the order. If you carry out the order, you cannot then blame the person who issued it, for you should not have listened to it. From the Jewish perspective, indeed from any religious perspective, God is on a higher plane than the person who gives the illegal order. One must follow the ethical commandments of the Torah and not an immoral one.
At the trials of the Nazi war criminals held after World War II, most Nazis offered the defence that they were only “following orders.” From the perspective of Jewish law, this was no defence. On October 29, 1956, the eve of Israel’s Sinai campaign against Egypt, the Israeli government feared a “fifth column,” and issued an order to Arabs living in Israel to remain inside their villages under curfew. At one Arab village, Kfar Kassem, some people went to work, apparently unaware that a curfew had been imposed. Israeli troops, encountering them, opened fire and killed forty-nine villagers. At their court-martial, the soldiers defended themselves with the claim that they were following military orders. The court rejected this defence and eight of the soldiers were convicted of murder. They should have known, the judges ruled, that it was immoral and forbidden to open fire on unarmed civilians. No “order” from a superior officer could justify what they had done.
Quite simply, according to Jewish law, if one is given an immoral order, one is obligated not to carry it out. If one does implement it, he or she is no less blameworthy than the person who ordered it. In the Talmud, this principle is known as “Ein shaliach le-dvar aveirah”. This expression means literally, “There is no messenger in a case of sin.” A messenger normally cannot be blamed for the contents of the message he delivers, no matter how ugly or infuriating it is. All blame should be directed at the one who sent the message. But if a messenger is sent to perform evil, he cannot defend himself by saying that he was only acting as someone else’s agent. Because “there is no messenger in a case of sin,” he bears full and personal responsibility for any evil he does.
Rabbi Adrian M Schell
(Source: J. Telushkin: Jewish Literacy )