Ugandan President Yoweri Museveni arrived in South Sudan Thursday after the arrest of First Vice President Riek Machar heightened fears of a return to civil war. Machar was detained last week by ...

President Salva Kiir's government has accused Machar, a longtime rival who led rebel forces during a 2013-18 war that killed hundreds of thousands, of trying stir up a new rebellion. Machar's ...