I have this utopian vision of being able to look back on this period of time as the tumultuous beginning of the end of powerful national militaries. In this utopia, military forces exist primariliy as a international coalition body tasked with the total elimination of groups like I-fuck-goats-sis, Boko Haram, etc. Maybe really antagonistic countries hold onto their (decreased) nuclear arsenal as a deterrent to other equally antagonistic countries, but by and large fissile material is used to build and supply reactors to start a massive desalination campaign anywhere it's needed.