Facing a tense diplomatic and moral crisis, the sons of Jacob presented a condition to the local leaders. On the surface, their response appeared to be an agreement to integrate, but it actually concealed a deep strategic plan. The primary approach among commentators is that the brothers expressed a willingness to consent to the requests of the townspeople [רש״י, רד״ק, מזרחי, ביאור שטיינזלץ]. They offered to allow the locals to benefit from their presence [תורה תמימה], serving as a bridge to achieve a shared existence [רש ר הירש]. They did not demand full civil rights, settling only for an agreement to live together as one people [מלבי״ם]. However, this consent was strictly general. While they agreed in principle to intermarry and dwell together, they never explicitly promised to give their sister Dinah to Shechem, as the tragedy of her defilement could not be undone. This careful distinction is evident in their demand that all the men of the city undergo circumcision, rather than just Shechem himself [ביאור יש״ר].
The requirement that the men of Shechem become just like the Israelites went far beyond a physical procedure. Because the Israelites viewed the uncircumcised state as disgraceful, they demanded true equality [ביאור שטיינזלץ]. This meant the people of Shechem had to accept the basic moral laws required of all humanity, abandon their idolatry, and undergo a genuine process of conversion. The brothers insisted that the townspeople cleanse their hearts before altering their flesh [הכתב והקבלה, פרדס יוסף, שפתי כהן, נחל קדומים]. The brothers assumed the townspeople would reject such a difficult and unnatural demand. A refusal would provide them with a justified reason to rescue their sister by force, as they believed any means was acceptable to save her from such a shameful situation [רש ר הירש, בכור שור].
Surprisingly, Shechem and his father agreed, but their motives were entirely corrupt. They had no intention of fulfilling the spiritual conditions of the agreement. Instead, they underwent the physical procedure solely to steal the Israelites' wealth and livestock [הכתב והקבלה, פרדס יוסף], while continuing to practice idolatry in secret [נחל קדומים, חומת אנך]. This lack of pure intention is the reason the men of Shechem suffered such intense pain on the third day. Had they been fulfilling a true Commandment, the joy of the act would have soothed their suffering. Because they were driven by greed, the procedure remained nothing more than a painful, empty physical act [פרדס יוסף].
When the brothers realized that the people of Shechem were planning to rob and kill them, and that they had completely violated the foundational condition to abandon idolatry, Simeon and Levi felt their harsh retaliation was entirely justified. Following the attack, Jacob chose to bury the foreign idols of Shechem rather than burn them. He did this so the idols would remain as physical evidence for anyone who might pursue them, proving that the townspeople had broken their treaty and that their punishment was deserved [הכתב והקבלה, נחל קדומים, חומת אנך].