Well, that's kind of the point of why they're well situated now. They've been invaded by basically everyone and nobody wants to do it again, and they've been diplomatically isolated in the past so they've kept a focus on self-sufficiency while maintaining decent enough relations with everyone.
As Civ 4 taught me, "It is from their foes, not their friends, that cities learn the lesson of building high walls."
Well, that's kind of the point of why they're well situated now. They've been invaded by basically everyone and nobody wants to do it again, and they've been diplomatically isolated in the past so they've kept a focus on self-sufficiency while maintaining decent enough relations with everyone.
As Civ 4 taught me, "It is from their foes, not their friends, that cities learn the lesson of building high walls."