Rabbinic Limitations on War

Deuteronomy 20 permits wars of aggression, but the talmudic rabbis made it difficult to declare one.

In Mishnah Sotah 8:7, Rabbi Yehudah designates an expansionary war of aggression a milhemet chovah, an obligatory war. The majority rabbinic opinion, however, calls these types of wars milhemet reshut, discretionary wars. Whereas Rabbi Yehudah’s designation recognizes these wars as expressions of God’s will, the rabbis’ designation divests it of religious significance. The following article describes how this and other rabbinic laws sought to limit the validity and practicality of violent conflict. Excerpted and reprinted with permission from S’VARA 2:1 (1991).

Discretionary Wars Do Not Exempt You From Mitzvot

When a war is obligatory, it has a priority status within the legal religious system, and one who engages in this war is exempt from fulfilling other commandments that claim one’s time and attention. A nonobligatory act [i.e., a discretionary act], however, has no such standing and does not provide such an exemption. Thus, discretionary wars must stand in line behind a lengthy and detailed list of mitzvot [commandments] that make daily if not hourly demands on every Jew.


For example, Talmud Torah [studying Torah], which one is obligated to do day and night, Shabbat, prayer, to name but a few, all take precedence over discretionary acts. Wars of aggression could thus become a permissible but rarely invoked policy. One opinion in the Gemara [Talmud] goes even further and attributes this position to Rabbi Yehudah as well, thus making wars of aggression milhemet reshut [discretionary wars] according to all opinions in the Mishnah. Though we cannot prove that the reclassification of aggressive war as milhemet reshut expresses a rabbinic critique of the biblical approach to war, the rabbis were fully aware of the implications of their legal innovation:

“One calls them commanded and the other voluntary, the practical issue being that one who is engaged in the performance of a commandment is exempt from the performance of another commandment.” (Sotah 44b)

If Sinners Cannot Fight, Then No One Can Fight

The philosophical shift away from Deuteronomy express a general purpose to limit, if not abolish, Israel’s aggressive military campaigns. This purpose is reflected in a rabbinic debate about Deuteronomy’s exemption for soldiers who are “afraid and disheartened.” Applicable only to discretionary wars of aggression (milhemet reshut), the exemption could be interpreted narrowly or broadly.

Rabbi Akiva reads the text narrowly; the only soldiers exempted are “…those unable to stand in the battle ranks and see a drawn sword.” Then the Mishnah records a disagreement between two rabbis favoring a broader reading:

“Rabbi Jose the Galilean says: afraid and disheartened alludes to one who is afraid because of the transgressions he had committed…Rabbi Jose says: A High Priest who married a widow, an ordinary priest who married a divorcee…a lay Israelite who married an illegitimate…behold such a one is afraid and disheartened.”

As interpreted by the Gemara [Talmud], this debate is perceived to be over which sins ought to prevent one from participating in a voluntary war, one arguing that the exemption only applies to violations of biblical law and the other, even the most minute rabbinic law.

Thus, from a biblical ordinance that saw soldiers who were afraid as counterproductive, the rabbinic tradition develops a new category for exemption: sin. It is not simply the psychological fear for one’s own safety due to one’s sinful past, for if so, there would be no grounds for distinguishing rabbinic from biblical law. If the person were afraid, regardless of cause, he would be destructive.

The language of Rabbi Jose in the Mishnah, “Behold such a one is afraid and disheartened,” is not an attempt to describe new causes for fear but to prescribe what one must be afraid of and thus to fix the occasions when one is excluded from participating in the war.

This broader reading, that it is the gravity of sin that ought to prevent one from participating in a discretionary war, leads to Rabbi Jose defending the view that the violation of the most minute rabbinic law (“speaking between donning one phylactery and the other”) constitutes a justification for exemption.

From this point it follows that because all Israelites are in reality violators of some rabbinic ordinance, there can be no Israelite army that is qualified to embark on a war of aggression. Wars of aggression are the right of a sinless people, an oxymoron.

Milhemet reshut [discretionary wars of aggression] might thus be loosely connected to a group of other laws, such as the law of the rebellious son which lo hayah v’lo nivrah, never was, nor was it ever meant to be implemented, but was written in the Torah so that we would learn it and receive reward for the learning alone without any intention of it ever being enacted.

You Can Fight, But First You Need to Ask Permission

Further, rabbinic law attempted to curtail and control the discretionary wars of Israel by legislating that the political leadership (the king) had no authority on its own to declare a milhemet reshut. “Discretionary wars can be waged only by the authority of a court of seventy‑one (Sanhedrin).” (Sanhedrin 2a; 20b)

In theory, it seems, the purpose of this legislation is to place discretionary wars under the authority of Judaism’s religious leadership and ensure that Israel does not become a warmongering nation drafted into the service of power hungry kings. The members of the rabbinic court, which is intimately aware of Judaism’s theological and ethical agendas, are thus the qualified guardians over a law that threatens these agendas.

Whether this rationale was borne out in practice is another matter. In fact, the one rabbinic reference for procuring sanction for voluntary warfare does not seem to present the Sanhedrin as a force in controlling or curtailing these immoral campaigns:

At the coming of dawn, the Sages of Israel entered into his presence and said unto him, “Our Sovereign King, the people Israel need sustenance.” “Go and support yourselves by mutual trading,” David replied. “But,” said they, “a handful does not satisfy the lion, nor can a pit be filled with its own clods.” Whereupon David said to them, “Go and stretch forth your hands with a troop (of soldiers).” Immediately they held counsel with Ahitophel and took advice from the Sanhedrin and inquired of the Urim and Tummin. (Sanhedrin 16a)

The Sanhedrin are here portrayed as a rubber stamp in an ongoing and prevalent policy of correcting the Jewish people’s financial woes with the aid of aggressive warfare.

Discretionary Wars Are Still on the Books

This last case is a good example of the limitations of rabbinic morality of war. Although creating legal criteria for exemptions from soldiering, and a decision process that institutes checks and balances before the Jewish people can legally embark on wars of aggression, this form of war was not abolished from the books. It became a voluntary war, which as such, was still legally permitted.

Only a people committed to using their legal exemptions, or a Sanhedrin pledged to peace and the abandonment of a policy of wars of aggression, would succeed in curtailing this immorality. No legal structure was set up to guarantee this result. As distinct from the laws of the rebellious son, voluntary wars of aggression and conquest remain formally and legally implementable.

When warfare is a not a practical option, such as was the case for much of Jewish history, gaps through which immoral discretionary wars can be justified are of less significance and their “plugging” is not a legal priority. With the return to statehood and military power, it becomes a serious concern that we have a legal system that maintains “on its books” the legitimacy of wars of pure aggression.

The total abolition of a law that reflected the policies of idealized kings such as David and Solomon was beyond the rabbis’ self‑perceived authority. The rabbis might have nullified the law with their restrictive ruling, but they were not inclined to morally condemn it. They chose instead to curtail its implementation, thereby creating a legal framework that enabled the people to see wars of aggression as a part of their history and not an ongoing political option.

In addition, in their commentary on Deuteronomy 20, where Jewish law legitimizes all the wars of the Jewish people regardless of their purpose and motivation, the rabbis place statements that speak to the centrality of peace. They argue, in essence, that although the Bible legally sanctions these wars, military aggression is antithetical to the ethos of the Bible itself, which, in their opinion, places a central emphasis on the significance of peace.

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