Rashi (32:23) writes that what happened to Dinah was a result of Ya'akov putting her in a box to keep her away from Eisav. Had Dinah married Eisav, she might have inspired him to do teshuvah, but thanks to Ya'akov, there was never a chance of that happening.
Why did the chance that Dinah might influence Eisav outweigh the potential danger of him influencing her, or her having a bad marriage? How does the benefit outweigh the downside risk? Why was Ya'akov wrong?
To compound the problem, the Midrash gives a completely different reason for what happened to Dina. In last week's parsha when Ya'akov made his deal with Lavan regarding which sheep Lavan would keep and which sheep would become part of Ya'akov's own flock, he told Lavan, "V'ansa bi tidkasi b'yom machar," my righteousness will speak for itself in the coming days. The Midrash (73:6) is critical of Ya'akov for this statement. "Al tishallel b'yom machar" -- you Ya'akov said "v'ansa... machar," therefore your daughter Dinah will suffer inuy at the hands of Shchem.
The first question that begs asking is what is the connection between Ya'akov's confident boast (if you will) to Lavan and what happened to Dinah. But secondly, which is it -- did Dinah come to harm at Shchem because Ya'akov put her in a box and kept her from Eisav, or because of what he said to Lavan?
Chasam Sofer explains that the two reasons go hand in hand. "V'ansa bi tidkasi b'yom machar" is a statement of tremendous bitachon. Ya'akov felt confident that what would happen would ultimately support his claims, his position, his righteousness because G-d had promised that no harm would come to him. The downside of boasting and being supremely confident based on bitachon is that you better be consistent, or you risk getting hoisted on your own petard (see this post.) Does someone completely confident that Hashem will protect him from all harm lock his daughter in a box? Ya'akov's own words to Lavan were the ruler against which his actions were judged, and he came up short.
I think this Chasam Sofer helps answer the question we started with. A normal person like me is bothered by the question of how we know Dinah would bring Eisav to teshuvah and not the other way around. But someone who is a big ba'al bitachon, 100% confident that Hashem will work things out in his favor -- that shouldn't be his concern. Hashem promised that he would come to no harm -- what's the issue?
Speaking of risk vs. reward, I saw a Brisker Rav quoted that I don't understand. Ya'akov said that if Eisav fights against part of the camp, "V'haya ha'machaneh ha'nishar l'pleitah," the other half will escape. How did he know that they will for sure escape? Rashi explains that Ya'akov meant that he will fight back and beat off Eisav. Mashma that Ya'akov knew that if he fights, he is going to win. So why did Ya'akov bother with the presents, the davening, etc. -- why not just fight and be done with it? QED, says the Brisker Rav, that you only fight when your back is against the wall and you've exhausted every other means of resolution at your disposal.
I don't understand how this Rashi supports making a blanket rule like that. Ya'akov may have been confident that he would win, but who says there would not be casualties? Maybe in the risk/benefit scale, the cost of even a victorious battle would have been greater than the cost of the presents sent to Eisav?
Last point for the week: the Chofetz Chaim asked why is it that the malach of Eisav, the yetzer ha'ra, came to fight davka against Ya'akov? Why did a bad malach not come to fight against Avraham or fight against Yitzchak?
The Chofetz Chaim answered that the yetzer ha'ra can tolerate a Jew doing chessed (Avraham), the yetzer ha'ra can tolerate a Jew doing mitzvos and avodah (Yitzchak), but the yetzer ha'ra cannot tolerate Torah. As long as a Jew is connected to Torah, "ohr she'bah machziro l'mutav" and the yetzer can never win. Therefore, it's against Ya'akov, the symbol of Torah, the yosheiv ohalim, that the heavy guns are brought out.