why should we fulfil our obligations to the mexicans before the arizonans? we should keep our obligations to our own country first. we literally cant fulfill all the obligations so some has to go. im not saying "screw mexico" but its a governments job to care for its own people at least before others.
Focusing entirely on the short term wellbeing of your own can be a big mistake. Sure, giving all the water to Arizona and ignoring the deal with Mexico is better for Americans long term. But what happens next?
Short term thinking is what gets us into these problems in the first place.
Sounds fair, as long as arizonians would stop culturing the crops painfully developped during thousands of years and generously shared with them by Mexicans (Tomatoes, pepper, corn), or Peruvians (Potatoes), or Argentinians and Bolivians (Peanuts), or Europeans (Onions, Lattice, Cabbage), or Africans (cup of coffee?), or Asians (return also the red jungle chicken please, and the apple native from Kazakhstan).
They can still culture the arizonian jackalope thistle and the sellfish redneck's muddy sweetgrass, and all the other members in the long list of wonderful crops developed there, of course.