Robert Zoellick

It is much harder for economies to prosper if they cannot sell to, buy from, invest with, and even transit their neighbors. Landlocked countries with failed or failing neighbors can lose access to the world economy.

By irreducibly complex I mean a single system composed of several well-matched, interacting parts that contribute to the basic function, wherein the removal of any one of the parts causes the system to effectively cease functioning.

The historical novelist has to consider what has actually happened, while the SF writer is dealing in possibilities, but they are both in the business of imagining a world unlike our own and yet connected to it.