Parashas Chukas includes the first instance of the nation of Israel conquering another nation’s territory. Immediately following Aharon’s death, the Torah tells us that the Canaanites attacked Israel, and even succeeded in taking captives. The nation prayed to Hashem, who delivered the Canaanites and their wealth to Israel. The property, as the people vowed, was consecrated to Hashem (see Rashi, Bamidbar 21:3). They also conquered the territory of Sichon and Og.
The Canaanites later became the chief adversaries of Israel, after Israel’s entry into the Land of Israel. Their mention in the context of war raises the halachic issue of warfare, and in the present article we will take up the specific issue of going to war on Shabbos. What kind of wars are considered milchemes mitzvah? Are there limitations on fighting defensive wars on Shabbos? And what is the halacha pertaining to preemptive strikes?
These questions, among others, are discussed below.
Milchemes Mitzvah: A Mitzvah War
Wars that are obligatory are called milchemes mitzvah. The classic case of a milchemes mitzvah is a war that Hashem explicitly instructs us to wage. However, there are also general categories for milchemes mitzvah, such as a war of self-defense (as noted by the Gemara, Sotah 44b).
The Rambam (Melachim 5:1) thus writes that one of the three categories of milchemes mitzvah (in addition to waging war against Amalek, and war against the Seven Nations of the Land of Israel) is saving Israel from their enemies.
Another category of milchemes mitzvah is a war undertaken to conquer Eretz Yisrael. The Ramban (Hasagot Lesefer Hamitzvos, Hosafos Le’mitzvos Aseh 4) writes that this is considered an obligatory war.
The example given by the Rambam for a non-mitzvah war—a discretionary war—is a war undertaken to expand the territory of the state, such as the wars fought by King David.
Going to War on Shabbos
The Gemara (Eruvin 45A) teaches: “Rav Yehuda stated in the name of Rav: If non-Jews besieged Israelite towns, it is forbidden to go forth against them or to desecrate Shabbos in any other way on their account.”
The Gemara qualifies the ruling: “This, however, applies only where they came for monetary matters. If they came with the intention of taking lives, the people are permitted to go forth against them with their weapons and to desecrate the Sabbath on their account.”
Clearly, a war that involves self-defense against a mortal threat can be fought even on Shabbos, the reason being that this involves pikuach nefesh, endangering lives. This of course also applies to terrorists planning an attack, in which case there is an obligation to stop them, even when doing so involves violating Shabbos.
The Gemara adds that for a border town, whose defense prevents a strategic danger to the other parts of the country, it is permitted to go to war on Shabbos even if the enemy’s intention is not to take lives but merely to “plunder straw or hay.” According to Rashi, the strategic loss of a border town involves a danger to the entire country, so that the issue amounts to pikuach nefesh. See also Meiri and Ritva for different interpretations of the Gemara.
The Rambam (Shabbos 2:23) and the Shulchan Aruch (Orach Chaim 329:6-7) rule these principles. The Shulchan Aruch adds that whenever the enemy comes against us with weapons, we assume they intend to take lives, and it is permitted to go to war on Shabbos.
He further rules: “In our times, even when the foreigners come only for monetary gain, we go forth against them on the Sabbath. For if the Jews do not let the non‑Jews plunder their possessions, they will kill the Jews.”
The assumption is that Jews will not allow non-Jews to simply steal their possessions, and therefore even when they come for a monetary gain it is likely that things will escalate into life-threatening situations (see Magen Avraham 329:5 and Mishnah Berurah 329:16).
The State of Israel recently engaged in numerous preemptive strikes, whose purpose was to diminish the threat of future attacks with advanced weapons. Is it permitted to engage in such strikes on Shabbos, where doing so will accrue some strategic advantage?
The Gemara (Sotah 44b) mentions a dispute concerning a campaign undertaken to weaken the non-Jews so that they should not fight against us. In one opinion, this is considered a milchemes mitzvah, while another opinion states that this is a milchemes reshus.
Later authorities differ on the question of how to rule on this issue. According to the Lechem Mishnah (Commentary to Rambam ibid), explaining the omission of the Rambam of this law, only a strictly defensive campaign is classified as a milchemes mitzvah. The category does not include preemptive strikes.
Others, however, dispute this point, and extend the scope of the term “to defend Israel against an enemy” to include a preventive war (see Knesses Hagedolah).
Yet, it is possible that when it comes to a milchemes mitzvah, it is permitted to embark even on an offensive campaign on Shabbos.
The Torah states: “You may cut [trees] down for constructing siege works against the city that is waging war on you, until it has been reduced” (Devarim 20:20). The Gemara teaches, citing a baraisa: “We do not begin a siege against a non-Jewish town in the last three days of the week. But if it was begun, we do not stop. Shammai used to say that ‘until it has been reduced’ means even on Shabbat” (Shabbos 19a).
We learn from here that it is forbidden to embark on a military campaign on Shabbos, and this is forbidden even three days before Shabbos. However, if a war starts before that and continues until Shabbos, we continue to fight even on Shabbos, even when no immediate danger to life is involved. The Rivash (Siman 101) explains that this is a special halacha of warfare, whereby it is permitted to conduct all aspects of the war even on Shabbos.
The Yerushalmi (Shabbos 13a) makes a distinction in this matter between a milchemes mitzvah and a milchemes reshus. The principles above apply specifically to a milchemes reshus, a non-obligatory war. However, for an obligatory war, it is permitted even to begin a campaign (a siege) on Shabbos. This also seems to be the opinion of the Rambam (Shabbos 2:25).
The ruling of the Rambam (as mentioned above), may be of relevance to our situation in Israel. Rabbi Eliezer Waldenberg (Shut Tzitz Eliezer 3:9, chap. 2, dated Adar, 1948) writing in the days of the Israeli War of Independence, that not only may defensive campaigns be fought on Shabbos, but it is even permitted to embark on an offensive campaign on Shabbos, where this relates to conquering the Land of Israel (see also Shut Yabia Omer 8:54, citing Panim Yafos).
As we have seen, gaining a significant strategic advantage (or ensuring that such an advantage is not lost) is considered pikuach nefesh even if there is no immediate danger. This is derived from the halacha relating to a border town, which can be defended on Shabbos even if there is no danger to life.
According to all opinions, it will therefore be permitted to embark on a military campaign on Shabbos, where doing so will gain a strategic or tactical advantage that can save lives.
Returning on Shabbos
The Rambam rules (Shabbos 2:23), “After they have saved their brethren, they may return home with their weapons on the Sabbath, so that a dangerous situation will not be created in the future.” This implies that it is permitted even to violate Shabbos (by travelling beyond the techum) in returning back to the base.
The ruling is based on the Gemara in Eruvin (45a), which relates that originally it was forbidden for people to return with their weapons after a military excursion, and they would leave them where they were. Yet, enemy forces soon understood that Jews were returning unarmed, and attacked them, causing the death of many. The Sages therefore permitted those who come to assist a besieged city to return with their weapons.
Some rule that this rationale applies even today. As it well known, Rav Moshe Feinstein (Shut Iggros Moshe, Orach Chaim Vol. 4, no. 80) relied on this principle to allow Hatzoloh personnel to return home from a hospital on Shabbos, out of concern that if they will not be allowed to return home, this might lead them to refuse to escort people to the hospital on Shabbos the next time they are needed. Many, including Rav Shlomo Zalman Auerbach, dispute Rav Moshe’s position on this since their return involves actions which are otherwise forbidden from the Torah. We will please G-d treat the question in depth in a future article.
Concerning the military itself, Rav Herzog (former Chief Rabbi of Israel; Shut Heichal Yitzchak, Orach Chaim 32) writes that the leniency applies specifically to volunteers, who might be reluctant to leave next time round, and not to paid soldiers. He also writes that the leniency only applies where there is actual fear of returning unarmed, but where there is no such fear, the leniency will not apply. Rav Eliezer Waldenberg (Shut Tzitz Eliezer, Vol. 4, no. 4) is likewise stringent on the matter (after much discussion of the subject).