Israel is also investing heavily in knowledge work and other high margin industries, as well as investing outside the country, in an attempt to get high margin, high value income to offset the dangerous economic risks they have, in part due to limited and expensive water - and which for very strong and fundamental religious reasons still gives a very, very strong incentive for them to stay and stay functional. Israel in particular has a history of wars and armed conflict around the Jordan River (November 1964 to May 1967 and others).
There is a saying in the West - Whiskey is for drinkin', water is for fightin' - and it is very apparent how true it is if you watch how things develop over time. Water is life in the desert.
Globally centralized allocation of resources would solve this, but that’s not feasible for a whole number of reasons, so instead it’s every desert for themselves.
Arizona is close to the ocean and has plenty of sunlight. Solar power + desalination will make this a non-issue in the next 40 years.