The plane from Egypt packed with a cache of weapons was meant to arrive in Somalia in May. But the two thousand Kalashnikovs, rocket launchers, sniper rifles, pistols and mortars never touched down. They were stopped, a senior Somali official told The Sunday Telegraph, because of fears in Mogadishu of Somalia being publicly drawn into a growing row between two of Africa’s superpowers. Egypt has been the dominant power on the Nile for thousands of years. But the balance of power is about to shift far upstream. In the next few weeks, when the rainy season arrives, Ethiopia will start to fill up a vast reservoir with the waters of the Blue Nile, one of the great river’s two main tributaries. One of Africa’s largest infrastructure projects will effectively give Ethiopia the power to turn off the taps in Egypt – and could force neighbouring countries to pick a side. For nearly a decade, Ethiopia has been constructing a one-mile-long wall of cement almost twice the height of the Statue of Liberty. The Grand Ethiopian Renaissance Dam, as it is known, straddles the Blue Nile, only a few miles from the border with Sudan.