At the time Ethiopia was under the Marxist regime of Haile Mariam Mengistu and had little chance of getting finance to build dams or little support world wide. The story is now different, which makes the more hawkish trend in the Egyptian military urge for a strategic control of Sudan to be able to carry out military operations, if needed in Ethiopia. The rational is to carry out vital work to protect the Aswan Dam. It creates barriers occurring every few hundred kilometres. If one collapses the zillions of tonnes gushing could wash the rest and destroy the dam.
Engineers study whether engineering and structural work is needed to avert such a disaster.
But in the late 20th century Britain is not in control of the African countries concerned while Sudan is no longer a de-facto province from which the Egyptian army can march unopposed southward. But the situation is also complicated by Geography. It embraces lakes Victoria, Albert, Edward and Keoga. The second group is the Semliki River tributaries mainly flowing Zaire and Uganda contributing 8.5 bn cubic meters annually before they join the other group north of lake Albert to form Bahr el-Jabal which holds 50 bn c meters. From this point it becomes the White Nile.