What qualifies as an obligatory [mitzvah] war? Defending Israel [the Jewish people] against an enemy.
MAIMONIDES, MISHNEH TORAH, LAWS OF KINGS, 5:1
In our exploration of the Torah’s military guidance, we have seen the importance of cultivating and heeding strategic military experts who are not compromised by complacency, or worse, by political considerations. We also studied a key proverb that, if practiced, would radically alter Israel’s security for the better.
When we further explore Torah sources, we see that halachah offers us a robust strategic defensive playbook. This strategic framework, which traces back to the Talmud and is codified in the Code of Jewish Law, was comprehensively elucidated by the Rebbe for contemporary Jewish self-defense.
The Rebbe offered an analysis relevant to a Jewish community anywhere in the world, while applying it to the Jewish state’s contemporary problems.
Talmudic Context
The Talmud1 discusses how Jews should respond to enemies who come to attack a city in terms of risk assessment. If foreign forces besiege a Jewish town on Shabbos, the appropriate response depends on their motives. If the enemy merely comes to steal, it is not necessarily permissible to resort to armed defense. If, however, they intend to injure or kill, or even if they come with unspecified intentions,2 the town’s inhabitants must defend themselves, even if this involves violating the laws of Shabbos.3
Moreover, the Talmudic passage continues to say that towns near the border must take up arms and violate Shabbos to defend themselves, even if the invaders’ sole motivation is to steal seemingly insignificant resources such as straw or hay. This is due to the strategic importance of border towns and the risk of minor conflicts escalating into more serious threats. In such a scenario, a proper show of force will deter future, potentially more dangerous, attacks. For these strategic reasons, maintaining absolute control over these locations is paramount, even if doing so requires violating Shabbos.
To emphasize this point, the Talmud relates that as a young man, King David risked his life to lead a Jewish militia against Philistines who were raiding the grain floors of the Judean town Ke’ilah.4 Even though the Philistines had only come to steal resources, G‑d instructed David to strike the Philistines since Ke’ilah was a border town.5
Notably, the Talmud issues its ruling regarding the protection of communities outside the Land of Israel, clearly establishing that the key guiding principle at play is saving lives, not defending our ancestral homeland.6 In the Rebbe’s words:7
This psak din [ruling] has its source in the Talmud (Eiruvin 45a), where the Gemara cites as an illustration of a “border-town” under the terms of this psak din [ruling] — the city of Neharde’a in Babylon (present day Iraq) – [which is] clearly not in Eretz Yisrael. I have emphasized time and time again that it is a question of, and should be judged purely on the basis of, pikuach nefesh, not geography.
The Halachic Verdict
The Code of Jewish Law (Orach Chaim 329:6-7) codifies the Talmudic ruling as follows:8
In a case where non-Jews besiege Jewish cities, [the course of action depends on the attackers’ intentions.]
If their intent is merely to steal or plunder property, we are not permitted to violate Shabbos in order to fight them.
If, however, their aim is to cause us harm, or even if their intentions are unclear, we [must preemptively] confront them with weapons and desecrate the Shabbos to fight them off.
When it comes to a border city, the rules are more stringent.
Even if the enemies are coming for insignificant items, such as straw or hay, we are obligated to desecrate Shabbos to fend them off.
Rema, a leading authority on Jewish Law, extends this ruling to apply in all cases, even to the mere threat of an enemy intending to come and attack or plunder:9
And even if the attackers have not yet arrived, but merely intend to come, Jewish defenders must preemptively take up arms [and neutralize the threat].
Shemiras Shabbos KeHilchasah,10 a major contemporary guide on Shabbos observance, states that in present-day Israel, it is imperative to violate Shabbos laws in order to defend the land against intrusions. This is because even if the intruders merely intend to steal, the situation could potentially escalate and turn dangerous. The intruders might realize that Shabbos and holidays are more vulnerable to attack, resulting in more severe threats.11
Let’s carefully unpack this section in the Code of Jewish Law, demonstrating how it forms a detailed playbook for Jewish self-defense.
Risk Assessment
The Code of Jewish Law states:
In a case where non-Jews besiege Jewish cities, the course of action depends on the attackers’ intentions.
If their intent is merely to steal or plunder property, we are not permitted to violate Shabbos in order to fight them.
This is a doctrine of risk assessment. The Code of Jewish Law challenges rabbis and local security experts to consider the intentions of any group that may harm the Jewish community. If the harm is purely financial – say they are merely looking to steal property – Jewish Law assesses two values: the value of Shabbos observance and the value of property.
In such a case, Jewish Law rules that the value of Shabbos observance overrides property loss. Shabbos is so fundamental to maintaining the fabric of the Jewish community and its relationship with G‑d12 that it trumps mere financial loss.
The Code of Jewish law then continues to say that while, fundamentally, one should not violate Shabbos over mere property thieves, practically, one should do so, since allowing property theft could easily escalate into more serious acts of violence.13 Thus, local security personnel must rely on their expert intuition and may desecrate the Shabbos if they judge that the theft could escalate into a situation endangering the local Jewish community. This is the consensus opinion among Jewish legal experts.14
This establishes the principle that when intentions are known and limited (theft), one response is prescribed. However, as we’ll see next, when intentions are unclear or potentially more threatening, the halachic response changes accordingly.
Risk Tolerance
The Code of Jewish Law continues, specifying:
However, if their aim is to cause us harm, or even if their intentions are unclear, we must preemptively confront them with weapons and desecrate Shabbos to fight them off.
This ruling embodies a fundamental principle of risk tolerance in Jewish Law. By mandating defensive action even when intentions are merely ‘unclear,’ the Code establishes an extremely low threshold for acceptable risk when Jewish lives might be in danger.
A critical factor of risk analysis in any domain is risk tolerance. Briefly, this evaluates: How much risk is acceptable? One can have a high risk-tolerance, meaning that they are willing to allow high degrees of risk, or a low risk-tolerance, which means that one has a much lower threshold before they will respond to a possible risk.
Less abstractly, a high risk tolerance would mean that one allows for a high probability that Jews may be killed due to some other value that they place above Jewish life – perhaps Shabbos observance, or maintaining a good image for the international community. Low-risk tolerance would mean that one would take action even to prevent a low probability that Jewish people will die.
Jewish Law positions itself firmly at the lowest end of this risk tolerance spectrum when it comes to threats against life. The Code makes clear that a Jewish community must not accept any level of risk when individuals might inflict bodily harm or engage in kidnapping.15 If hostile groups harbor such intentions, they must be neutralized, even if doing so violates the core Jewish value of Shabbos observance. This near-zero risk tolerance extends further: even if the invaders’ intentions are unclear, Jewish defenders must preemptively confront and neutralize the threat.
Well-Meaning Passivity Is Not an Option
In response to those who take a more thoroughgoingly spiritual view, suggesting we should simply pray for safety in Israel and not take concrete defensive measures, the Rebbe countered:16
Some argue that since Jews require Divine assistance in order to be saved, they should focus on reciting Psalms and studying Torah instead of arming themselves and violating Shabbos. However, the Code of Jewish Law [unequivocally] rules that we must also arm ourselves and go out to fight.
We are obligated to act in accordance with the Code of Jewish Law, echoing the example set by Jacob, who, while initially praying, also prepared himself for war by “confronting them [Esau’s hostile army] with weapons.”
Reinforcing this point even further:17
Beis Yosef [the author of the Code of Jewish Law] was familiar with the verse, “The voice is the voice of Jacob.”18 Moreover, he himself studied Torah with dedication and intensity, surpassing today’s Torah scholars. Yet, he ruled that in such a situation, we must “confront them with weapons and desecrate Shabbos,” since G‑d wants us to operate within the natural order.
Having explored the elements of risk assessment and tolerance, we will delve further into the Jewish strategic playbook, exploring the special case of land. In a previous class, we discussed why one would have to be incredibly naive to believe that land concessions will mollify Israel’s enemies. In the upcoming class, we will explain the strategic value of land and why the Torah teaches that conceding land can lead to disaster.
Exercises:
- Comment below: This class emphasizes that these laws are based purely on pikuach nefesh, not defending the holy land. What are the implications of grounding defense policy in universal life-saving principles?
- Comment below: How might this principle apply to Jewish communities in the diaspora today facing security threats?

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