How will this resolve in the event of a proxy war? I'm Egypt funds or arms a rebel groupor neighboring army? What if the Egyptian army trains that group directly?

@m2 this is asking about a direct confrontation

Ethiopia is filling a big new dam on the Nile called the Grand Renaissance Dam. Egypt worries this will take away water they need. So far, Egypt and Ethiopia have avoided war and tried negotiations. But talks have stalled. Egypt might keep pushing diplomatically and try to get other countries to help put pressure. However, if Ethiopia keeps filling the dam and negotiations totally fail, Egypt's leaders might consider military options in the future. Especially if they need to look strong for their people. Still, war would be very costly and damaging for both countries economies. Ethiopia could be cautious with the dam to avoid conflict. New technological solutions could also help share water. While risks exist, Egypt and Ethiopia likely want to avoid direct war in this decade.                                            

Walsh, D. (2021, April 8). Are Egypt and Ethiopia heading for war over water? The New York Times. https://www.nytimes.com/2021/04/08/world/middleeast/egypt-ethiopia-nile-dam.html

Tadesse, K. (2022, September 24). Can new tech help ease Egypt-Ethiopia Nile dam tensions? AP News. https://apnews.com/article/technology-business-environment-and-nature-ethiopia-africa-c202bf1d5d4a4d87957b664cc4b84b24

This is prevented by the government collapsing.