On page 82a of shabbat the Mishna talks about the levels of tumah involved in “avodah zarah”. The Talmud explains a situation where a Jew and “avoda zara” share a wall between their buildings or structures. If the wall falls down the Jew must rebuild the wall within his 4 amos of property so as not to benefit the Avodah Zarah.
The Shikker Dovid would like to learn two important lessons. First, clearly this situation makes the Jew and non-Jew neigbhors, thereby obligating the Jew to act correctly and respectfully to his neighbor. The Talmud is implicitly providing a situation where Jew must live in harmony and interact with the non-Jewish world. This is clearly not the shtetl model of living. Jews can live around and amongst non-Jews.
However, the second lesson is that although we can live amongst non-Jews and must accord respect and friendship, the wall teaches us the limitation of how much we can absorb or engage. The proximity to Non-Jews is acceptable, our interactions must be neighnborly and respectful. We can learn from them. The rebuilding the wall on our side teaches us that there is a distinction or a line not to cross. The question the Shikker dovid cannot answer is : “Where is that line drawn?”