Tension in East Africa is rising after Ethiopia's prime minister this weekend rejected Egypt's suggestion the World Bank arbitrate ongoing disagreements over the construction of a dam on the Nile River. The stakes are high for both countries. #160;Ethiopia says the $5 billion hydroelectric dam will provide power to millions in desperate need of electric power. #160;Egypt says it will disrupt the flow of water from the Nile, jeopardizing agriculture in the country. Ethiopia anticipated the dam, now in its seventh year of construction, would be completed last year, but the project...