The conduct of war: lessons from Deuteronomy 20

By Hetty Lalleman 03 Dec 2004

Warfare has been part of human life from early times. It is one of the consequences of what happened in Genesis 3 – rebellion against God. The Old Testament is not a book which only contains pious phrases about human beings and God. Of course, God reveals himself in the Bible, but he does so throughout real history of human beings, who indeed are very human from time to time.

The people of Israel are not a religious community living in a vacuum. On the contrary, they are a real nation in a world surrounded by foes and occasionally a few friends. God has chosen one particular people to be his ‘example’ in the world with the purpose of making his deeds and ways known . In the Old Testament this occasionally happens through words, but mainly through Israel’s presence and way of life.

In the Book of Deuteronomy we find all sorts of laws given to Israel before they entered the promised land. In this context of how to live life as the people of God there are laws about warfare, since Israel as a political entity was living in a real, often dangerous world. In the Ancient Near East warfare was more or less ‘normal’ and necessary, and kings were highly praised for their victories, as can be seen in the Assyrian reliefs in the British Museum. Is Israel different in this respect?

The distinctiveness of Israel

According to Deuteronomy 20 it should be. When we take a closer look at the laws on warfare there are several striking features to be noticed. In the first place, there is no command to expand the land by war. There is no motive for imperialistic warfare. Warfare is part of life, but it is not essential in order to enlarge God’s ‘territory’ or to ‘prove’ God’s greatness, a motive found in other nations such as the Assyrians.

Israel is unique in that it does not automatically identify the God of Israel with the land of Israel. The Old Testament is concerned with the relationship between God and his (covenant) people, and this relationship even exists before they live in the promised land. In this sense, God is not a ‘territorial God’, as are those from the other nations surrounding Israel. Of those nations, Daniel Block remarks: ‘Deities were primarily attached to specific geographic territories and only secondarily concerned with the inhabitants of those areas.’ [1]

The God of Israel is different and so should his people be. Although the land is a very important factor in the Old Testament, in the laws of the Torah no glorification can be found of Israel’s political power. In fact, her power is very restricted.

This is made explicit in the first four verses of Deuteronomy 20. It is the Lord God who gives the victory over other nations with their ‘horses and chariots’, indicating great military forces. In the next five verses the Israelite army is even diminished: those who have a new house, or who have just planted a vineyard or who are newly married, let them go and enjoy their blessings in the promised land. Those who are fearful should go home as well. A wonderful illustration of this ‘army diminished’ is found in the story of Gideon (Judges 7:3). The fact that Israel’s existence is not centred on military power is also illustrated in the law on kingship in Deuteronomy 17:14–20. Gordon McConville remarks on the passage: ‘It is clear that Deuteronomy aims to circumscribe the powers of the king… Unlike other ancient kings, he does not fight battles, maintain a harem, or even acquire wealth.’ [2]

If we take a further look at Deuteronomy 20:10–15, we read that to cities at a distance, peace was to be offered before anything else happened. If such cities answered in a positive way, they could remain in their own land and be subject to Israel. They were not to be ill-treated. If, however, they refused to make peace, Israel was to go to battle. Women and children might be taken captive in such cases, but in Deuteronomy 21:10–14 we read some humane regulations about captive women. If an Israelite married such a woman, he was not allowed to sell her or treat her as a slave if he were no longer pleased with her. She should be treated as a valuable human being.

At the end of the passage there are some other rules to govern warfare: in times of war fruit trees were not to be destroyed or cut down to be used for siege works. This is in marked contrast with the custom of the Assyrians. When a city did not submit to them, they would usually withdraw and burn and destroy the harvest, the trees and the houses of the surrounding areas.

The destruction of the Canaanites

Some verses in the middle of Deuteronomy 20 (16–18) offer an emotional (or theological) problem to many readers. What about the extinction of the Canaanites? Let me make two important remarks on the issue. Regarding one of those peoples, the Amorites, Genesis 15:16 says that their wickedness is the cause of them being driven out of the land. After his promise to Abraham concerning the land, God had given peoples like the Amorites some time to change and to convert, but now their sin has ‘reached its full measure’ (see also Deuteronomy 9:4). [3] So there is definitely the element of God punishing the Canaanites for their wicked behaviour.

In addition to this, there is another motive for the strict rules about driving them out of the land: they are a danger to Israel because of their idolatry. This motive is clearly stated in verse 18. If Israel does not completely destroy them, ‘they will teach you to follow all the detestable things they do in worshipping their gods, and you will sin against the Lord your God.’

Therefore, warfare against the Canaanites is not a matter of imperialism, hatred or cruelty. It is about Israel preserving its identity as a people committed to the one and only God. And it is certainly not true that Israel was meant to fight permanently against everyone who was not Israelite! So the idea that the whole Old Testament is about wars (which I’ve so often heard people saying) is definitely wrong! [4]


To sum up some essential features of Deuteronomy 20: Israel is not meant to be an imperialistic empire with a strong ruler. Warfare is not glorified, but the first aim is peace. The ‘ideal’ king David is not allowed to build the temple because of all the blood he has shed (1 Chronicles 28:3), whereas Assyrians kings would be highly respected because of all the wars they had fought! What then can we learn for the twenty-first century?

  • The basic issue in destroying the Canaanite peoples was the fact that Israel had to get rid of everything which might lead them away from God, because this would mean the end of their very existence as the people of God. In the ongoing ‘battle’ of the Christian life, Jesus says that as Christians we too should do away with everything which distracts us from God. We should clear our lives radically from everything which leads us to sin. Matthew 5:29–30; see also Matthew 18:8–9 and Mark 9:43–48.
  • Deuteronomy 20 restricts human power in battle, and in the same way Deuteronomy 17:14–20 restricts the earthly power of the king. Both these texts warn us today not to glorify human beings and human powers. The church should be brave in protesting against the deification of military, economic or political powers, because they are a form of idolatry. [5]
  • There are Christians involved in warfare, because we must live in this world. Some have chosen not to be involved in the army, police force, etc. (cf. the Mennonites). For those who have and who are in leadership positions, some principles of Deuteronomy 20 might be helpful. Human power should be limited (see above). Warfare is not the ultimate purpose of a nation; peace is the goal. Imperialism and aggression should never be regarded as ‘normal’. Furthermore, captives should be treated in a humane way, and environmental warfare should be forbidden.
  • There is one warning from our investigation to be taken to heart: since the Christian church is not a political entity, it cannot be acceptable when ‘Christian’ nations wage war ‘in the name of God’. We should be very cautious not to acclaim anyone as a ‘godly king’ or ‘godly ruler’, or our own country as ‘God’s country’.
  • Do these things apply to nations with a majority of non-Christians as well? In the oracles against the nations, the Israelite prophets show us that God will judge them according to their behaviour. Thus Amos 1–2 gives a list of violent crimes perpetrated by the surrounding nations. All nations should thus listen in to what God said to his people Israel about the conduct of war in Deuteronomy 20.

[1] Block, D. The Gods of the Nations: Studies in Ancient Near Eastern National Theology (Leicester & Grand Rapids: Baker / Apollos, 2000), pp. 32 & 150.

[2]   McConville, J. G., Deuteronomy (Apollos Old Testament Commentary; Leicester & Downers Grove: Apollos / InterVarsity Press, 2002), p. 34.

[3] See also C. J. H. Wright, Old Testament Ethics for the People of God (Leicester: IVP, 2004), ‘What about the Canaanites?’, pp. 472–480.

[4] In this context it is worth looking at the way some of the other nations, except the Canaanites, were treated, see Deut. 2. The outcome of the assessment of other peoples depends on their attitude and relationship to Israel. If they are positive towards her, they will share in her blessings (see also Gen. 12:3).

[5] Cf. Bob Goudzwaard, Idols of our time (Downers Grove: IVP, ET, 1984); Walter Wink, Engaging the Powers. Discernment and Resistance in a World of Domination (Minneapolis: Fortress, 1992).

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