The world is re-arming. It’s tempting to see this as part of a broader revival of nationalism driven by populists like Modi and Putin. On the contrary, argues Faisal Devji, it is a crucial part of a slow-motion collapse of nation states. Armed forces lie at the heart of national sovereignty, yet from Israel to India they are hiring mercenaries and allowing their centralized command structures to crumble. Nations are thereby ceding the monopoly of violence on which they depend to increasingly autonomous, unwieldy militaries.