A leader of the independence movement in Western Sahara has died. Mohamed Abdelaziz was the leader and co-founder of the Polisario Front movement, which has demanded independence ever since Morocco took over most of Western Sahara in 1975. In March, Morocco expelled United Nations staffers from Western Sahara after U.N. Secretary-General Ban Ki-moon visited the region and used the term “occupation” to describe Morocco’s relationship to Western Sahara.