John Robb's larger theory is a further development of the theories on asymmetric warfare "fourth generation war" and the dissapation of the nation state's monopoly on force. Specifically, he is researching how a kind of open source model is being used by guerillas/terrorists/organised criminals to increase their capabilities, and he's rather "bullish" about that. The decline of the nation state has long been predicted by related military scholars, like Martin van Creveld. Robb thinks that nation states (being stupid) are now accellerating a process that was already well underway.

Now aside of reading Robb's blog and some newspaper articles on it I don't know this theory directly, so I don't know exactly how Robb's thinking fits in. Basically, though, you can see there being roughly three or four determinants of the decline and fall of the nation state.

The first, about which I'm not really sure, is failing primary loyalties. This is an ideological issue, but it doesn't exist everywhere (it does exist more in the third world than in the first).

The second and main determinant is technological change. It's ever easier for people to get access to tools with which they can exercise, project & coordinate force.

The third issue is the global capitalist system. Nation states rely on its functioning for their economic growth. However, the system (by unconscious (hidden hand) design) has a very low degree of resilience because it has a high level of interrelation coupled to a low level of redundancy. (We've had discussions on this topic on ET before, IIRC)

The fourth would be tactics. Because of their open source structure the global guerrillas function better in the current information environment.

What comes after the nation state depends upon how drastic the consequences of their collapse are. So, you can design various scenarios and speculate.

For instance, if the collapse of the nation state is not accompanied by a dowfall in economic activity of more than 30-50%, I'd say that it is quite probable that in America and Europe we'll see something much like the anarcho-capitalist dream becoming reality (privatisation of force, justice for those who can afford it, the poor out-lawed and excluded). In much of the third world there will be a reversion to tribalism mixed with mercenary armies, resource theft and piracy at sea as continual agents of chaos blocking the (re-)emergence of nation states.

If the collapse is bigger, then the level of technology will also fall and the set of circumstances that favoured the collapse of the nation state (the way that power/force is distributed and structured) will no longer exist. So after the population is much diminished we'll see the re-emergence of nation states.