Oil and gas discovers in East Africa have re-ignited long-standing territorial disputes in areas believed to possess significant petroleum deposits. This week, Malawi announced it would take Tanzania to the International Court of Justice in The Hague, Netherlands, over the disputed ownership of Lake Malawi, known in Tanzania as Lake Nyasa. Tanzania claims that colonial era treaties between Great Britain and Germany demarcated the border down the middle of the lake but since independence Malawi has claimed sovereignty over the whole of its northern reaches.