Halakhah su Deuteronomio 20:8

And the officers shall speak unto the people, saying: who is the man who has built a new house and has not begun living in it? let him go and return to his house, lest he die in the battle and another man begin living in it. And who is the man who has planted a vineyard and has not redeemed [its fruit in the fourth year]? let him go and return to his house, lest he die in the battle and another man redeem it. And who is the man who has betrothed a wife and has not taken her? let him go and return to his house, lest he die in the battle and another man take her.¹The immediately following verse, Deuteronomy 20:8, provides yet another exemption: “And the officers shall speak further unto the people and they shall say, who is the man who is fearful and faint-hearted? let him go and return to his house, and let him not make the heart of his brethren faint as [is] his heart.” This exclusion, however, applies with regard to milḥamot miẓvah as well as to milḥamot reshut; see Radbaz, Hilkhot Melakhim 7:1, and commentaries ad loc.

In order properly to understand the consideration underlying the requirement of the urim ve-tumim as a necessary condition of halakhically sanctioned warfare, a somewhat extraneous matter which is nevertheless germane to this topic must be examined. The categories of milḥemet mizvah and milḥemet reshut pertain only to wars fought by Jews. Other than in the context of war, self-defense or execution of transgressors convicted of capital offenses, the taking of human life is forbidden to both Jew and gentile alike. Since, insofar as non-Jews are concerned, there are no biblically sanctioned modes of war analogous to war for the conquest of the land of Canaan or the war against Amalek, it might well be presumed that non-Jews may not legitimately engage in warfare other than for the strictly limited purpose of self-defense. Indeed, a number of eminent authorities, including R. Moses Sofer, Teshuvot Hatam Sofer, Yoreh De'ah, no. 19, R. Abraham Dov Kahana-Shapiro, Dvar Avraham, I, no. 11, and R. Menachem Ziemba, Zera Avraham, no. 24, adduce explicit talmudic authority in ruling that non-Jews are prohibited from engaging in war.⁵³See Contemporary Halakhic Problems, II, 165. Nevertheless, an opposing view is found in the writings of one noted authority.⁵⁴A similar view, albeit not based on the same line of reasoning, is espoused by Maharal of Prague in his supercommentary on Rashi, Gur Aryeh, Parshat Va-Yishlah, s.v. she-ha-umot. In explaining the action taken by the sons of Jacob against the inhabitants of Shechem, Maharal states that the family of Jacob constituted a sovereign people and were permitted to do battle against another nation since war is not forbidden under the Noachide Code. R. Naphtali Zevi Yehudah Berlin, in his commentary on the Bible, Ha'amek Davar, Genesis 9:5, finds justification for the view that the taking of human life in the course of war does not constitute culpable homicide.⁵⁵This view is also expressed in Ha’amek Davar, Deuteronomy 20:8. See also Amud ha-Yemini, no. 16, chap. 5, secs. 8-24. The verse "But your blood of your lives will I require; from the hand of every beast will I require it; and from the hand of man, from the hand of a person's brother, will I require the life of man" (Genesis 9:5) contains one phrase that is an apparent redundancy. The phrase, "from the hand of man … will I require the life of man" pronounces man culpable for the murder of his fellow. To what point, then, is it necessary for Scripture to reiterate "from the hand of a person's brother will I require the life of man?" Fratricide is certainly no less heinous a crime than ordinary homicide. Ha'amek Davar understands this phrase as placing a limitation upon the nature of culpable homicide. The taking of human life constitutes homicide only when the relationship between the parties is analogous to that which exists between a man and his brother, i.e., during periods in which harmony and brotherly love may be anticipated to reign between them. War, however, is the antithesis of brotherhood. Under such conditions, maintains Ha'amek Davar, there is no punishment for taking human life. Since this verse occurs in the context of the prohibition against homicide as it pertains to Noachides, Ha'amek Davar concludes that gentiles are not culpable for the taking of human life within the context of warfare.

One latter-day authority does find grounds upon which to rule that non-Jews who engage in war are not guilty of murder. R. Naphtali Zevi Yehudah Berlin, in his commentary on the Pentateuch, Ha'amek Davar, Genesis 9:5, finds dispensation for warfare in the very verse which prohibits homicide to the Sons of Noah: "And surely your blood of your lives will I require … and at the hand of man, at the hand of every man's brother, will I require the life of man." The phrase "at the hand of every man's brother" appears to be entirely redundant since it adds nothing to the preceding phrase "at the hand of man." Ha'amek Davar understands this phrase as a limiting clause: "When is man punished? [If he commits homicide] when it is proper to behave in a brotherly manner." However, in time of war when animosity reigns among nations the taking of life in the course of military activity is not punishable. Again, in Ha'amek Davar, Deuteronomy 20:8, this authority states that "even" a Jewish monarch may engage in battle, thereby implying that gentiles are certainly not prohibited from doing so. Earlier, Maharal of Prague, in his commentary on the Bible, Gur Aryeh, Parshat Va-Yishlaḥ, speaking of the action taken by the sons of Jacob against the inhabitants of Shechem, states that the family of Jacob constituted, in effect, a sovereign people and were permitted to do battle against another nation since war is not forbidden under the Noachide Code. This position is, however, contradicted by a number of other authorities. R. Moses Sofer, Teshuvot Hatam Sofer, Yoreh De'ah, no. 19, declares wars of aggression to be forbidden to Noachides under all circumstances. In support of his position, Hatam Sofer cites the discussion found in Sanhedrin 59a. The Gemara declares that non-Jews do not enjoy legal prerogatives of conquest (lav benei kibush ninahu). Hatam Sofer demonstrates that the Gemara, Gittin 38a, does indeed affirm that non-Jews may acquire title to lands captured in wars by virtue of conquest. The phrase "lav benei kibush" must then be understood, argues Hatam Sofer, as meaning that non-Jews have no right to engage in war for purposes of conquest even though post factum they may acquire title in this manner. The identical argument is advanced by R. Abraham Dov Ber Kahane, Dvar Avraham, I, no. 11 and by R. Menachem Ziemba, Zera Avraham, no. 24. These authorities are in agreement with Hatam Sofer's view that non-Jews may not engage in a war of aggression under any circumstances.