The disputed oil-rich Iraqi city of Kirkuk, claimed historically by both Kurds and Turkmen, encompasses all of the major challenges that impact the country as a whole -- sectarian clashes, security crises, disputed natural resources, forced displacement, and foreign political involvement. A referendum will determine whether the city will become part of the semi-autonomous Kurdistan region or part of greater Iraq. Left unresolved, tensions between the different ethnic communities in Kirkuk could exacerbate conflicts throughout the country.