Historically, Egypt and Sudan constructed major dams over the Nile, notably the Aswan High Dam and the Sennar Dam, without notifying and seeking consent from other basin states, including Ethiopia.
However, Ethiopia constructed the GERD, notifying the lower stream states, in a diplomatic and brotherly gesture, in stark contrast to Egypt's colonial mindset of utilizing the Nile waters.
Ethiopia committed to the Declaration of Principles (DoP) in 2015, acknowledging the need for cooperation, fair use, and non-harm, setting a standard for consultation, and nullifying the colonial era agreement.
Ethiopia is the source of the Abay River, contributing over 86 percent of water to downstream states.
Egypt had been a safe haven for violent groups engaged in destabilizing Ethiopia, providing trainings and logistics to separatist groups to undermine Ethiopia.
Author's summary: Egypt's colonial approach to Nile water is outdated.