How could a city be viable if the soil surrounding it has become hostile to any kind of crop? What would the options be?
I came up with the idea of establishing settlements around the city, miles away, where the soil allows to plant and which would send the most part of the harvests to the capital. But, first: how could you protect those settlements? They are far away, too far for news of an attack to travel to the capital and then the reinforcements get to the settlement. In any case, imagining those settlements grow into proper villages or towns with the capability of self-defense, without being dependent on the capital in that regard, at this point we would be facing another problem: these villages/towns now need more food for a larger population, so they can't send as much of their crops to the capital, so they longer fulfill their purpose.
Let's say there's no revolt, no movement against the capital. I need the capital to survive because it's key to the story. How can the capital not only survive, but be solvent? I mean, to have some kind of response capability against an attack (resources-wise), and not just being an agonizing place that can be taken over by a bunch of crooks.
Well, that was my idea, I'd love to read yours! Any politics you can think of that could be put in practice? Any take on the matter will be welcome.
Thank you all in advance.