(FILES) Polisario fighters patrol near the 1600kms long, Moroccan defensive walls, 15 June 1988, in Polisario-controlled Western Sahara. The Polisario Front threatened 21 December 2007 to resume war against Morocco if the negotiations in New York 07-09 January 2008 to end the conflict fail. The Polisario front, an armed movement backed by Algeria, is fighting for the independence of Western Sahara, a former colony of Spain that was invaded and annexed by Morocco in 1975. AFP PHOTO / MIKE NELSON (Photo credit should read MIKE NELSON/AFP/Getty Images)