The Morality of this event is discussed in a seperate post.

The scholarly consensus is that this war did not take place. The entire Exodus and conquest narrative is contradicted by virtually all archaeology and history of the region.

Some further problems:

1) This second generation of Israelites suffered not a single casualty throughout Numbers 26–36. The claims that 12,000 Israelite soldiers exterminated or captured the entire Midianite population and destroyed all their towns without suffering a single casualty are held to be historically impossible, and should be understood as symbolic.

2) Despite Moses slaughtering every last one of the Midionites, other biblical books set in later times continue to refer to them. For example, just a few decades later in Judges 6-8, the Midionites are back, now easily dominating the Israelites with an army of 135,000 (each of whom had a sword! Impressive economy…).

3) Olson (2012) noted that the name Kozbi comes from the Hebrew consonants kzb, meaning “to lie, deceive”; the idea that Kozbi deceived the Israelites is emphasised in verse 25:18: “The Midianites deceived you with their tricks in the matter of Peor and in the matter of Kozbi, the woman who was killed to stop the plague.” This suggests she was not a historical character, but invented as a metaphor for danger to the Israelites.

4) Midianites or Moabites – Moses is said to have made the following connection: “The Midianite women were the ones who followed Balaam’s advice and enticed the Israelites to be unfaithful to Yahweh in the Peor incident, so that a plague struck Yahweh’s people.”

This contradicts verses 25:1–3, which states the women were Moabites, and verses 25:16–18, in which Yahweh himself claimed that the plague did not hit the Israelite camp until Kozbi entered it, leading Yahweh to instruct Moses to kill the Midianites, not the Moabites.

This has puzzled scholars. Knohl (1995) argued that the original text (preserved in 25:1–5) had Moabite women as the main characters, but the editor (seeking to legitimise Phinehas and his descendants’ claims to the priesthood) replaced them with Midianite women in a sloppy manner so that the resulting new text (25:6–18 and all of chapter 31) confused the two tribes.

5) According to the Book of Exodus, the Midianites had sheltered Moses during his 40-year exile after killing an Egyptian (Exodus 2:11–21), the Midianite priest Jethro/Reuel/Hobab acted positively towards Yahweh in Exodus chapter 12, and his daughter Zipporah became Moses’ wife.

Scholars find it difficult to explain how Moses commanded the Israelites to exterminate and enslave the entire Midianite people while having a Midianite wife and father-in-law.