In a major breakthrough, South Sudan’s rival leaders sealed an agreement Sunday on a key military provision of their faltering peace deal following mediation by neighbouring Sudan. President Salva Kiir and his rival, Vice President Riek Machar, agreed on the creation of a unified armed forces command, one of several crucial unresolved issues holding up implementation of the 2018 deal to end the country’s bloody five-year civil war. “Peace is about security and today we have (achieved) a milestone,” said Martin Abucha, who signed the agreement on behalf of Machar’s opposition party the SPLM/A-I…