This week’s parasha is a story of unconventional warfare. On the heels of last week’s account of harlotry and zealotry in the Israelite camp, in our Parasha God tells Moshe to go to war against the Midianites, “for they are enemies to you, in their plottings against you on the matter of Peor, and the matter of their sister Kozbi, daughter of the prince of Midian, who was slain on the day of the plague…” Later in the Torah, it will be decreed that because of these actions, no member of the nation of Moav will be allowed to join with the nation of Israel.
It’s worth noting that this sort of decree of intergenerational enmity is not the norm: in other cases, the Torah instructs Israel to act charitably toward members of nations that had in prior generations oppressed or gone to war against Israel. Only in three cases is enmity proclaimed into future generations. One of those cases was the instruction to make war on Amalek, because the Amalekites attacked the stragglers of the Israelite camp in the desert. The other two cases come up in our parashah—that of the Emorites and Moabites, who were to be considered as enemies of the nation of Israel even ten generations after the last hostile contact with them. What is the source of this enmity?
A crime worse than murder?
The Midrash Rabbah asks the same question and provides a far-reaching answer:
|R’ Shimon says: One who causes a man to sin is even worse than one who kills him? After all, the one who murders removes his victim from this world but not the next; but the one who causes another to sin removes him from this world and the next. From where do we know this? Two nations advanced against Israel with the sword, and two with transgression. The Egyptians and the Edomites advanced against them with the sword, as is proven by the texts, “The enemy said: I will pursue, I will overtake . . . I will draw my sword” (Exodus 15:9), and “Edom said unto him: You shall not pass through me, lest I come out with the sword against you” (Numbers 20:18). Two advanced against them with transgression, namely the Moabites and the Ammonites. Of those who had advanced against them with the sword it is written, “You shall not abhor an Edomite . . . you shall not abhor an Egyptian” (Deuteronomy 23:8). Of those, however, who had advanced against them with transgression, endeavoring to make Israel sin, it says, “An Ammonite or a Moabite shall not enter into the assembly of G‑d . . . even to the tenth generation shall none of them enter . . . forever” (ibid. v. 4).
— Midrash Rabbah, Pinchas
צָרוֹר אֶת הַמִּדְיָנִים. למה?… רַבִּי שִׁמְעוֹן אוֹמֵר מִנַּיִן שֶׁהַמַּחְטִיא אֶת הָאָדָם יוֹתֵר מִן הַהוֹרְגוֹ, שֶׁהַהוֹרֵג הוֹרֵג בָּעוֹלָם הַזֶּה, וְיֵשׁ לוֹ חֵלֶק לָעוֹלָם הַבָּא, וְהַמַּחְטִיא הוֹרְגוֹ בָּעוֹלָם הַזֶּה וּבָעוֹלָם הַבָּא. שְׁתֵּי אֻמּוֹת קִדְמוּ אֶת יִשְׂרָאֵל בְּחֶרֶב, וּשְׁתַּיִם בַּעֲבֵרָה, הַמִּצְרִים וַאֲדוֹמִים קִדְּמוּ בְּחֶרֶב (שמות טו, ט): אָמַר אוֹיֵב אֶרְדֹּף אַשִֹּׂיג, אָרִיק חַרְבִּי. (במדבר כ, יח): וַיֹּאמֶר אֵלָיו אֱדוֹם לֹא תַעֲבֹר בִּי פֶּן בַּחֶרֶב אֵצֵא לִקְרָאתֶךָ. וּשְׁתַּיִם בַּעֲבֵרָה, מוֹאָבִים וְעַמּוֹנִים, עַל אֵלֶּה שֶׁקִּדְּמוּ בְּחֶרֶב, כְּתִיב (דברים כג, ח): לֹא תְתַעֵב אֲדֹמִי (דברים כג, ד): לֹא תְתַעֵב מִצְרִי, אֲבָל אֵלּוּ שֶׁקִּדְּמוּ בַּעֲבֵרָה לְהַחְטִיא אֶת יִשְׂרָאֵל (דברים כג, ד): לֹא יָבֹא עַמּוֹנִי וּמוֹאָבִי, גַּם דּוֹר עֲשִׂירִי, עַד עוֹלָם.
The sin of the Midianites is not in attacking Israel, for which they might have been forgiven, but rather, in causing the Israelites to go astray.
But why is this seen as such a grave issue—so grave, in fact, that the tribe of Moav was considered to be a perpetual enemy to Israel? What actually was the crime of the Midianim? Was this a deliberate act of unconventional warfare? Or was it simply the meeting of the Israelite culture with the Midianite fertility cult? From the text, it would appear that the Midianim were well aware of the disastrous consequences of their cultural assault on the Israelites:
|Israel settled in Shittim, and the people began to commit harlotry with the daughters of Moab. They called the people to the sacrifices of their gods, and the people ate, and bowed down to their gods. Israel joined himself to Baal Peor, and the anger of G‑d was kindled against Israel.|| וַיֵּשֶׁב יִשְׂרָאֵל, בַּשִּׁטִּים; וַיָּחֶל הָעָם, לִזְנוֹת אֶל-בְּנוֹת מוֹאָב. וַתִּקְרֶאןָ לָעָם, לְזִבְחֵי אֱלֹהֵיהֶן; וַיֹּאכַל הָעָם, וַיִּשְׁתַּחֲווּ לֵאלֹהֵיהֶן. וַיִּצָּמֶד יִשְׂרָאֵל, לְבַעַל פְּעוֹר; וַיִּחַר-אַף ה’ בְּיִשְׂרָאֵל.
The clash of civilizations
The Torah calls attention to two dangers facing the Israelites in their encounter with the Midianim. The first is the danger of cultural assimilation, a danger that the Jews of the United States and the Soviet Union, each in different measure, know all too well. Such a clash of cultures need not involve violent subjugation; it is possible for a culture to succumb to too much love just as surely as to oppression. The Israelites who fell victim to this cultural conquest were those who had been raised in the desert, as is made clear in the verses that follow. They had no memory of the flight from Egypt or the miraculous events at Mt. Sinai, and were thus far more vulnerable to this clash of cultures.
The second risk is not so much cultural as moral, and this is the source of the perpetual enmity between Moav and Israel. In his monumental work Mishne Torah, the Rambam (Maimonides) sets out a list of those who may never be able to do Teshuvah.  Among these is one who causes others to sin. This, says the Rambam, is an avon Gadol—a great crime.
This was the crime of the Midianim. One who causes another to go against his better nature, and against his own conscience, potentially destroys his victim from within. Nor is it only one life that he destroys, but potentially a great many lives. The act of leading others astray can have consequences that are beyond anyone’s power to estimate. The human capacity to do either good or evil is simply inestimable. One who causes others to do evil turns the infinite potential of a human being into a force for destruction and unleashes it upon the world. It is like lighting a fire among dry thorns, not caring that the flames may spread to engulf whole forests and towns.
If the victim of this manipulation remains aware of what he is doing, he may still have the potential for Teshuvah and return. But what if he becomes insensitive to the harm that he causes? In that case, like his destroyer, even the chance for Teshuvah is taken from him. To strip a human being, created in the Divine image, of this choice is a terrible thing. It is a kind of spiritual murder. If we mourn the Temple through fasting and lamentations, which was built by human hands, how much more should we mourn the moral destruction of a human soul, which no human hands can restore?
The long view
But even in such a case as this, the Rambam doesn’t say that Teshuvah is altogether impossible, nor does he call the lack of Teshuvah a punishment. Rather, he implies that these behaviors so blind the soul to its own worth and that of others that the possibility, or even the need, for T’shuvah never arises. In the case of the cultural warfare of Moav, the rift between the two nations was healed only hundreds of years later, in the story of Ruth.
One of the lessons of Parashat Pinchas is that there are things more devastating than war, and there are wounds to the human spirit that can take generations—sometimes many generations—to heal.
 Temple prostitution was a well-established practice in the ancient Near East. In an earlier story, Tamar may have disguised herself as such a prostitute (a Kedusha) in tempting Yehuda. Could the story of the Midianite women be an incident in dialog with that earlier incident?
 Hilkhot Teshuvah 4:1.