GEN694 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 to 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 (this verse, with Ha’amek Davar commentary).   That is why the verses in Ecclesiastes say in one verse that “there is an appropriate time (and reaction) for war,” and “an appropriate time (and reaction) to hate. Ecclesiastes 3:8.  AMJV 67