HARDtalk's Stephen Sackur speaks to Nigeria's Army Chief, Lieutenant General Tukur Yusuf Buratai. Nigeria's stability and unity is threatened by internal tensions, conflict and corruption. From the Boko Haram insurgency in the north to violent militancy in the south and separatist aspirations in the east. Amid all this turmoil, how effective in securing the country is the Nigerian army? Show less