When the Jews were leaving the wilderness, there was the very unpleasant episode with the daughters of Midian. It was, at its core, a twinned assault of idolatry and adultery; the sexuality of the foreign women led Jewish men astray in their relationships with both their wives and with G-d .
What is unnoticed is how an infiltration of foreign influences was possible in the first place. After all, theoretically, the Jews were susceptible the entire time they were in the wilderness, but no such “attack” on the morals of the nation occurred in all that time.
The obvious answer is that, as the Midrash tells us, the clouds of glory accompanied the Jewish people in the wilderness, and protected them on all sides. They were a literal buffer for the nation, keeping us safely insulated from outside influences, able to mature and grow in a virtual bubble.
But when Aharon died, shortly before the events of the daughters of Midian occurred, the clouds of glory disappeared just as the Jews were entering more populated areas. The transition had begun; the Jews were going from being a protected nation to being a nation that had to learn how to interact with the rest of the world. The daughters of Midian were the first test, and one that the nation, save for Pinchas’ quick action, failed.
But note how G-d reacts. He does NOT tell the Jewish people to erect their own version of the clouds of glory, to find new ways to buffer and insulate ourselves from the outside world. Instead, he tells the Jewish people to go to war against Midian, and destroy them, men, women, and male children. Yet the virgins and chattels are kept and used.
There is a profound lesson in this, applicable to our lives today. We, too, are beset with foreign influences, and certainly by almost-unlimited sexual temptations from the outside world. It is directly analogous to the situation with Midian. But if we are to learn the lessons of the Torah, the answer is to engage with the enemy, to counter the negative elements that they bring. Nonetheless, in the end, as with the Midianite girls and chattel, we are safe to assimilate those items that we can harness to our purposes, both sacred and mundane.