GEN1421 Rabbi Naftali Tzvi Yehuda Berlin, in his commentary to the Torah, states that in a time of legal war against Israel, many of the concepts governing Judaism are changed, and it may be appropriate to kill people (even innocents) when it is not normally permitted t do so.  He says that in the time of war, the rules are different and that innocent people may be killed if necessary to defeat the enemy.   Genesis 9:5 with Ha’amek Davar commentary.   That is why the verses in Ecclesiastes 3:8 say in one verse that “there is an appropriate time (and reaction) for war,” and “an appropriate time (and reaction) to hate.”  This idea also helps us understand how Maimonides could rule that Simeon and Levi were justified in killing all the people in the city of Shechem when, in reality, only their leaders actually kidnaped and raped their sister Dina.   Nachmanides takes strong issue with Maimonides and states that Simeon and Levi were wholly unjustified in killing the entire townspeople for their heinous acts of the leaders.   Nachmanides commentary on Genesis 34:13;49:5.   Wherein rests the argument between Maimonides and Nachmanides? In his Torah commentary, Maharal helps resolve the argument.   He explains that if Simeon and Levi were reacting to individuals who kidnaped and raped their sister, then they were not justified in killing the entire city’s people (the approach of Nachmanides-Ramban). But if this was a war between two peoples, between the Jewish nation and the tribe of people living in Shechem, then in war it is totally justified to kill the people in the entire town, even if they are civilians, as a means of defeating the enemy (the approach of Maimonides-Ramban). Gur Aryeh commentary on Genesis 34:13.  In Judaism, the laws of war are distinct from those governing personal or collective self-defense.  AMJV 67