When the iron curtain dividing Cold War Europe fell, world leaders extolled a new era of freedom and openness. And yet, decades later, the business of constructing barriers is pursued with ever greater physical, financial, and ideological vigor, from the Middle East to the wealthiest societies of the West. Why have walls—be they municipal, regional, or international in scope—become the preferred means of resolving conflicts and addressing (or avoiding) civil unrest? This program investigates in a variety of socioeconomic contexts. Viewers are confronted with the geopolitics of urban and cultural segregation as seen in Iraq, Brazil, and France—and the results are sure to invite parallels with other global hot spots. (53 minutes)