geneva south sudan hellish war get bad neighbor let president salva kiir hold election accept peacekeepers ceasefire political opposition u.n. investigators say wednesday south sudan plunge civil war 2013 kiir fell deputy riek machar since 50,000-300,000 people die accord african union au millions displace push brink famine story absolutely unimaginable cruelty yasmin sooka head u.n. commission human right south sudan tell news conference geneva last year machar flee retreat kiir force spark new conflict equatorias region boost opposition kiir dinka tribe almost one four south sudanese belong kiir mandate expire april make clear want new election would catastrophic sooka fellow commissioner godfrey musila say democratic dinka president elect musila say dinka stay power militarily police state outside power must urgently find way generate legitimate government say first task fully deploy 4,000-strong regional protection force kiir east african bloc igad agree year ago although limit capital juba force would create condition opposition return would free u.n. peacekeepers go afield help bring ceasefire opposition military supply line would accept musila say 400 force arrive far sooka say best tool get action hybrid court au south sudan agree set base mix laws prosecute suspect include top political military figure sooka almost prosecutorial mandate u.n. human right council plan team 16 grind week include forensic analysts military advisers monday south sudan justice minister paulino wanawilla unango tell council government still incorporate last year agreement igad sooka say au must ensure consequences government fail take necessary step gambia january intervene oust president yahya jammeh west africans camp outside gambia tell president go armies come say east african community igad south sudan vote would heap disaster upon catastrophe u.n. say