Note: The earliest rabbinic texts excerpted here are from the Mishnah and date from approximately 200 C.E. This date is used to identify this article. Later rabbinic texts are given estimated dates below. Rabbinic discussions frequently build upon biblical texts from centuries earlier, some of which are given below with their approximate dates.
Biblical Texts
Deuteronomy 20 [ca. 7th century B.C.E.]
10When you draw near to a town to fight against it, offer it terms of peace. 11If it accepts your terms of peace and surrenders to you, then all the people in it shall serve you at forced labor. 12If it does not submit to you peacefully, but makes war against you, then you shall besiege it; 13and when the LORD your God gives it into your hand, you shall put all its males to the sword. 14You may, however, take as your booty the women, the children, livestock, and everything else in the town, all its spoil. You may enjoy the spoil of your enemies, which the LORD your God has given you. 15 Thus you shall treat all the towns that are very far from you, which are not towns of the nations here. 16But as for the towns of these peoples that the LORD your God is giving you as an inheritance, you must not let anything that breathes remain alive. 17You shall annihilate them—the Hittites and the Amorites, the Canaanites and the Perizzites, the Hivites and the Jebusites—just as the LORD your God has commanded, 18so that they may not teach you to do all the abhorrent things that they do for their gods, and you thus sin against the LORD your God. 19If you besiege a town for a long time, making war against it in order to take it, you must not destroy its trees by wielding an ax against them. Although you may take food from them, you must not cut them down. Are trees in the field human beings that they should come under siege from you?
Isaiah 2:3-4 [ca. 700 B.C.E.]
Many peoples shall come and say,
“Come, let us go up to the mountain of the LORD,
to the house of the God of Jacob;
that he may teach us his ways
and that we may walk in his paths.”
For out of Zion shall go forth instruction,
and the word of the LORD from Jerusalem.
He shall judge between the nations,
and shall arbitrate for many peoples;
they shall beat their swords into plowshares,
and their spears into pruning hooks;
nation shall not lift up sword against nation,
neither shall they learn war any more.
I Chronicles 22:7-9 [ca. 425 B.C.E.]
David said to Solomon, “My son, I wanted to build a House for the name of my ETERNAL God. But the word of GOD came to me, saying, ‘You have shed much blood and fought great battles; you shall not build a House for My name, for you have shed much blood on the earth in My sight. But you will have a son who will be a man at rest, for I will give him rest from all his enemies on all sides; Solomon will be his name and I shall confer peace and quiet on Israel in his time.
Rabbinic Texts
Mishneh Torah, Kings and Wars 5:1-2 [ca. 200 C.E.]
A king should not wage other wars before a milchemet mitzvah [commanded war]. What is considered as milchemet mitzvah? The war against the seven nations who occupied Eretz Yisrael, the war against Amalek, and a war fought to assist Israel from an enemy which attacks them.
Afterwards, he may wage a milchemet hareshut [war of choice], i.e. a war fought with other nations in order to expand the borders of Israel or magnify its greatness and reputation.
There is no need to seek the permission of the court to wage a milchemet mitzvah. Rather, he may go out on his own volition and force the nation to go out with him. In contrast, he may not lead the nation out to wage a milchemat hareshut unless the court of seventy-one judges approves.
War, neither a milchemet hareshut or a milchemet mitzvah, should not be waged against anyone until they are offered the opportunity of peace as Deuteronomy 20:10 states: 'When you approach a city to wage war against it, you should propose a peaceful settlement.'
If the enemy accepts the offer of peace and commits itself to the fulfillment of the seven mitzvot that were commanded to Noah's descendants, none of them should be killed. Rather, they should be subjugated as ibid. states: 'They shall be your subjects and serve you.'
Mishneh Torah, Kings and Wars 6:7-8
When a siege is placed around a city to conquer it, it should not be surrounded on all four sides, only on three. A place should be left for the inhabitants to flee and for all those who desire, to escape with their lives, as it is written [Numbers 31:7]: 'And they besieged Midian as God commanded Moses.' According to tradition, He commanded them to array the siege as described. We should not cut down fruit trees outside a city nor prevent an irrigation ditch from bringing water to them so that they dry up, as Deuteronomy 20:19 states: 'Do not destroy its trees…
bSan 72a [ca. 600 C.E.]
And the Torah stated a principle: If someone comes to kill you, rise and kill him first.
bYoma 22b [ca. 600 C.E.]
And he further reasoned: If the men have sinned (1 Sam 15), in what way have the animals sinned? Why, then, should the Amalekites’ livestock be destroyed? And if the adults have sinned, in what way have the children sinned? A Divine Voice then came forth and said to him: “Do not be overly righteous” (Ecclesiastes 7:16). That is to say: Do not be more merciful than the Creator Himself, Who has commanded you to do this, for to do so would not be an indication of righteousness but of weakness. At a later time, when Saul said to Doeg: “Turn around and strike down the priests, and Doeg the Edomite turned around and struck down the priests, and he killed on that day eighty-five men who wore the linen ephod, and he struck Nob the city of priests by the sword, man and woman alike, infants and sucklings alike, oxen and donkeys and sheep, by the sword” (I Samuel 22:18–19), a Divine Voice came forth and said to him: “Do not be overly wicked” (Ecclesiastes 7:17).
Ramban (Nachmanides) on Deuteronomy 20:1:1 [12th century C.E.]
WHEN THOU GOEST FORTH TO BATTLE AGAINST THINE ENEMIES, AND SEEST HORSES, AND CHARIOTS etc. This is a new commandment which he now declared to them as they came into battles. The purport of the verse, For the Eternal your G-d is He that goes with you, to fight for you against your enemies, to save you is to admonish them against becoming faint-hearted and that they should not fear their enemies. He states that they are not to rely in this matter on their own strength, thinking in their hearts: We are mighty men, and valiant men for the war …
