For example:
If thou go out to fight against thy enemies, and the Lord thy God deliver them into thy hand, and thou lead them away captives,
Poorly chosen quote, as that doesn’t authorize assault, as you’ve suggested. Let’s repost that from a current Catholic translation (I think yours is the Kings James version, with its archaic English). It then comes out as:
When you go out to war against your enemies and the LORD, your God, delivers them into your power, so that you take captives, 11if you see a beautiful woman among the captives and become so enamored of her that you wish to have her as a wife, 12and so you take her home to your house, she must shave her head,* cut her nails, 13lay aside her captive’s garb, and stay in your house, mourning her father and mother for a full month. After that, you may come to her, and you shall be her husband and she shall be your wife. 14If later on you lose your liking for her, you shall give her her freedom, if she wishes it; you must not sell her for money. Do not enslave her, since you have violated her.
Still sounds pretty harsh, but let’s consider something further. What was the norm in the ancient world for the defeated? This was actually a restraint on that allowing for marriage and basically the same rights as a Jewish woman would have had, after marriage.
This gets to the poorly understood concept of slavery. Slavery is never approved of in the Bible, but that it existed is acknowledged. In Hebrew and Aramaic the word for “servant” and “slave” were in fact the same. Why was that?
The reason for that was that they lived in different economic times than we do, and that any human has lived in since vast antiquity. With thin resources, the ability to buy and sell your labor, as we do now, was simply non existent in many circumstances. People who worked in certain occupations were basically indentured into those occupations for life, there being no other real choice. That’s the nature of the classical slavery of the ancient world.
This is not to suggest that it was kind in all instances, that would certainly be in error. But even in what seems to be harsh circumstances, such as slaves generated by war, ancient societies basically had no other means by which to handle it. They couldn’t let a surrendered force simply go, as it would come back. A common practice amongst many ancient people was simply to kill a lot of the defeated. Slavery at least allowed the defeated to live.
This is striking in comparison to North American slavery which had no such economic of social “justification”, if a person wishes to call it that, whatsoever.
This is one of those sections of the Old Testament that has to be understood in context. In the context of the ancient world, brutality by the victors over the defeated was the norm, not the exception. The section quoted actually imposes restraint upon the Israelite’s in comparison to the norm at the time, holding basically that women were not to be taken as prizes (a la ISIL today), but rather if one of the victorious Israelite combatants was taken with a woman, he had to marry her, and acknowledge her loss.
It also doesn’t have much to do, in this instance, with the Natural Law, fwiw.