It will be, or, it's slowly happening already. Climate change is triggering water and food shortages, both abroad and on your doorstep (California wildfires), which in turn trigger mass migrations. If a richer and/or more militarily equipped country decides they want another country's resources to survive, we'll see wars erupt everywhere.
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)
California moves water the long way with aqueducts, pipes and pumps. It's an understood problem, but expensive.
> it's more of a logistics challenge
and a bureaucratic one as well. in Germany, they want to trim bureaucratic necessities while (not) expecting multiple millions of climate refugees.
lot's of undocumented STUFF (undocumented have nowhere to go so they don't get vaccines, proper help when sick, injured, mentally unstable, threatened, abused) incoming which means more disease, crime, theft, money for security firms and insurance companies, which means more smuggle, more fear-mongering via media, more polarization, more hard-coding of subservience into the young, more financial fascism overall, less art, zero authenticity, and a spawn of VR worlds where the old rules apply forever.
plus more STDs and micro-pandemics due to viral mutations because people will be even more careless when partying under second-semester light-shows in metropolitan city clubs and festivals and when selling out for an "adventurous" quick potent buck and bug, which of course means more money pouring into pharma who won't be able to test their drugs thoroughly (and won't have to, not requiring platforms to fact check will transfer somewhat into the pharma industry) because the population will be more diverse in terms of their bio-chemical reactions towards ingredients in context of their "fluid" habitats chemical and psycho-social make-ups.
but it's cool, let's not solve the biggest problems before pseudo-transcending into the AGI era. will make for a really great impression, especially those who had the means, brains, skills, (past) careers, opportunity and peace of mind.
I was in Egypt a while and there's no talk of them invading Sudan or Ethiopia. A lot of Egypt's economy is overseas aid from the US and similar.
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.