The United Nations and African Union on Thursday ended a 13-year mission to keep the peace in the vast Sudanese region of Darfur, even as recent violent clashes leave residents fearful of renewed fighting. Fighting erupted in Darfur in 2003, when ethnic minority rebels rose up against the Arab-dominated government in Khartoum, which responded by recruiting and arming notorious Arab-dominated militia known as the Janjaweed. A total of 300,000...