In other words, if human nature were not fundamentally Hobbesian, why would states have the same types of fear that ultimately permeates and creates the anarchy of the international system as envisaged by neo-realists? 

The system’s structure is a reflection of the pieces of which it is comprised, just as the strucutre of a great cathedral or modern skyscraper is a reflection of the architects and designers that make it.  Granted, the international system is not “designed” by a single grandmaster, but it IS designed by a multitude of smaller, little “masters” such as national leaders, political opposition parties, non-state actors, etc that are in constant conflict either real, or just as importantly, perceived.

Ironically, even domestic politics is anarchic.  The difference is that there is a sovereign with the capacity to enforce discipline and/or enough commonality amongst the population that coercion is not an essential tool because it limits the scope of the anarchy to more predictable boundaries.  If the sovereign does not continue to retain its coercive  capacity and/or there is less commonality amongst the population, the the state itself essentially withers away and we are confronted with full blown anarchy akin to the state that exists between states (see Somalia as a contemporary example). 

Therefore, realism, in all its grim outlook, is fundamentally sound.  It cannot offer specific solutions to policy questions, but it most certainly can shape the prism through which policymakers view the facts they must interpret to reach policy decisions."