A Kosovo police officer guards a street in northern, Serb-dominated, part of ethnically divided town of Mitrovica, Kosovo, on Dec. 9.Bojan Slavkovic/The Associated Press Serbia’s prime minister said Friday the country’s leadership was close to demanding the deployment of their security troops to Kosovo, claiming lives of minority Serbs there were being threatened. The return of Belgrade’s troops to the former Serbian province could dramatically increase tensions in the Balkans. Serbian officials claim a U.N. resolution that formally ended the country’s bloody crackdown against majority Kosovo Albanian separatists in 1999 allows for some 1,000 Serb troops to return to Kosovo....