On Wednesday, Kosovo closed its largest border crossing with Serbia in response to more blockades, this time on the Serbian side of the border. Ethnic Serbs on the Kosovo side have been building barriers, too, in protest against the Kosovo government. The tensions are centered on the city of Mitrovica, where the population is majority Serb. Host Marco Werman speaks to journalist Tim Judah, who writes for The Economist. He recently returned from Kosovo and joins the show from London.