People tend to reside near those similar to them. This tendency is so prevalent, that you can assume with a high degree of likelihood that the food on your table is the same as on your neighbor's; that the musical tastes of your neighbor's children is close to that of your children, and that the TV shows you watch, your clothes, and the ballot you place in the box come election day are very much alike.
It's enough to point out where someone lives to outline a statistical profile of him. This is an uneasy thought, as it does not sit well with long-lasting and heartfelt aspiration shared by most and intensified following the ideas promoted by the Enlightenment – the aspiration for individuality, which finds itself caged by sociology.
But the unease is not shared by all. Large groups in the population have no interest in freedom of choice. While many reside where they do out of inertia, completely unaware of the hidden motive for their choice, others make a conscious decision. I mean conservative groups, for whom keeping together aids in the preservation of their traditions. The most extreme example are Naturei Karta ("Guardians of the city"), who fortify themselves in a limited geographic space, aiding them to discipline members of their community, punish those who stray and block strangers from seeping between the cracks in the city wall and undermining them from within.
But we shouldn't be unjust. I remember the conflicts which tore apart the kibbutz movement in the 50s. Kibbutzim divided not over differing lifestyle opinions, since they all believed in communal living and everyone wore the same clothes and celebrated their secular holidays together, but over faith in Soviet Russia. This nonsense was enough to expel people from communities they themselves raised, establish new kibbutzim and prohibit their children from meeting their childhood friends.
The geographic segregation enables the entrenched to maintain their unity, and their unity encourages entrenchment in camps. The Zionist ruling idea was "one nation," but it appears the battle between trends of unification and division within Israeli society was decided in favor of the latter. The unificationist rhetoric ("The shared fate of the Jewish people") and the touching attempts to promote brotherhood (meetings between secular and religious, Arab and Jewish youth) retreat in the face of hostile ideologies and the uncompromising economic facts. This influences the building up of the physical fortifications.
Beit Shemesh is an example: Even the traditionalists, to their different factions, want to distance themselves from each other. Obviously, tolerance levels drop as the community becomes more conservative. Liberal seculars can accept, though not without effort, those who differ from them in beliefs and lifestyle, but haredim harass the different, not out of malice but because they're afraid their being will be endangered. Haredim can find a place in a secular majority, and seculars escape from haredi-majority communities.
And this is the map which arose out of the "one nation" ideal's defeat: Bankrupt haredi cities where no secular treads, impoverished Arab towns where Jews fear to traverse, Jewish communities which exclude Arabs, affluent compounds inside which the only poor who get to sneak a peak are east Asian servants, neighborhoods home to migrant workers and the outcasts of society, towers of penthouses, guarded closely by suspicious security, fence-bound settlements, "lone ranches" and bypasses.
It seems to me that in the whole of the land there's only one strip, a kilometer and a half long, where the "one nation" exists in relative comfort - the first boulevard planted in the first Hebrew city: Rothschild Boulevard, between Allenby Street and Habima Square. A pathetic vestige compared to the vision which guided the returning Zionists.