Putting it in these terms, what I'm trying to say is something like:

  geography → economy → old empire

  geography → economy → current day politics

The biggest caveat to this is that the importance of geography is conditioned by technology, and technology changes over time. So a more detailed model could be something like:

  geography + current tech → agriculture/commerce/industry/military → economy/culture → politics

See how the dominant powers changed with the shift from bronze to iron or with the development of open ocean navigation.