U.N. Secretary-General Antonio Guterres says he wants to revive negotiations to resolve the Western Sahara conflict, which has seen Morocco and the Polisario Front independence movement go at each other for forty 40 years. In a report to the UN Security Council this week, Guterres proposed relaunching the negotiations “with a new dynamic and a new spirit.” He said the goal should be reaching “a mutually acceptable political solution” that would include “an accord on the nature and form that the exercise of self-determination” would take for the disputed and mineral-rich Western Sahara area. Morocco annexed Western Sahara, a former Spanish colony, in 1975 and fought the Polisario Front, which wanted to create an independent state in the territory. The UN negotiated a cease-fire in 1991 and established a peacekeeping mission to monitor it and to help arrange for a referendum on the territory’s future – but the referendum has never taken place.