The first daf (page) of Masechet Megillah focuses on the distinction between open and walled cites, regarding the timing of the reading of the Megillah. While one might have argued that, almost by definition, whatever is outside of a walled city cannot be part of the city protected with a wall, the Gemara quotes the view of Rav Yehoshua ben Levi—without quoting a dissenting view—that "a walled city and all that is adjacent to it and that is seen with it is judged like a walled city" (Megillah 2b).
“And Haman said to King Achashverosh: There is a certain nation scattered and divided amongst the nations” (3:8). Haman was well aware of the Achilles heel of the Jewish nation, the divisiveness that so often characterizes our community. As a small nation, lacking (at that time) a homeland, such unity is much more crucial for our survival than for that of other nations. When we are divided, we are weak; and when we are weak, we are vulnerable. Haman could thus request that, “if it pleases the king, let it be written to destroy them”.