maybe i am getting to old or to friendly to humans, but it's staggering to me how the priorities are for such things.
That doesn't seem to be much of a thing these days. If you look at Russia/Ukraine or China/Taiwan there's not much scarcity. It's more bullying dictator wants to control the neighbours issues.
Then again, it's more of a logistics challenge, and if e.g. California were to invade Canada for its water supply, how are they going to get it all the way down there?
I can see it happening in Africa though, a long string of countries rely on the Nile, but large hydropower dams built in Sudan and Ethiopia are reducing the water flow, which Egypt is really not happy about as it's costing them water supply and irrigated land. I wouldn't be surprised if Egypt and its allies declares war on those countries and aims to have the dams broken. Then again, that's been going on for some years now and nothing has happened yet as far as I'm aware.
(the above is armchair theorycrafting from thousands of miles away based on superficial information and a lively imagination at best)
The main military thing going on there - I was in Dahab where there are endless military checkpoints - is Hamas like guys trying to come over and overthrow the fairly moderate Egyptian government and replace it with a hardline Hamas type islamic dictatorship for the glorification of Allah etc. Again it's not about reducing scarcity - more about increasing scarcity in return for political control. Dahab and Cairo are both a few hours drive from Gaza.
The rest is fees from the Panama (EDIT: Suez) Canal and tourism. Getting into a war, particularly with a country on the Red Sea, is suicide. (Also, the main flash point between Egypt and Ethipia has receded since the GERD finished filling.)