Here's some fun thinking (at least I enjoyed it):
The most elegant approach to social collapse and renewal is Joseph Tainter's excellent, "The Collapse of Complex Societies". He makes the case that complex societies are (at root) problem solving systems (a very Boydian or Robbian approach). As new problems erupt (enemies, environmental problems, etc.), society's evolve solutions that add to their cumulative complexity (the society's toolset). Eventually, a complex society reach a point of maximal complexity (due to the constraints of its underlying organizational platforms/design) as its "solutions" suffer diminishing returns -- as in, the benefits derived from new laws/institutions/plans approach the costs of implementing them.
When benefits are equal to or less than costs, a society is ripe for collapse and replacement. Societies can skirt this edge for decades until something pushes/tips them over the edge.
Internally Driven Collapse
The method of collapse favored by Tainter is a tipping point is defined by a fundamental change (assumption level) in the underlying costs of running the society. He maintains that every great society is driven to the heights of its organizational potential by leveraging a "free" (for all intents an purposes) energy input. Unlimited access to this energy resource allows them essentially "free" problem solving and rapid recovery from mistakes. However, once that "free" energy becomes erratically available or expensive, the cost/benefit equations of many (if not most) of that social system's evolved solutions turn decidedly negative. Collapse, at that point, is inevitable. In our case, this "free" energy input would be fossil fuels (the negligible cost of which underwrites all social solutions).
Externally Driven Collapse
I'd like to offer another cause of collapse using this model: the threat of barbarians (relatively small and socially cohesive groups that prey on a rich society). In a society that has reached the limits of its organizational complexity, every attempt to counter barbarians generates negative returns. Every barbarian engineered looting event, every war to counter barbarian incursions, and every barbarian engineered crisis brings a complex society closer to bankruptcy and collapse. In our current case, it would be the combined effects of successful societal looting by aggressive tribes of banksters (several hundred thousand technologically superior financial warriors) and disruption from violent groups emerging within the growing number of weak spots of the global social fabric. Both are what I term global guerrillas.
Will we be able to meet the challenges posed by these barbarians?
Think about the efficiency of the solutions to Iraq and Afghanistan and the cost/benefit equation they represent -- or worse, the mindset that keeps us paying for a defensive system that guards against a great power war that won't ever come and the efficiency of the proverbial GWOT.
Think about how efficiently the global system responded and put down growing insurgencies in Mexico, Nigeria, and Pakistan (hint: they didn't).
Think about the benefits/costs derived from the shadow banking system (CDSs, CDOs, etc.) and the ability of the current social system to control it. Think about how the financial barbarians have convinced governments that private gains and socialized losses are acceptable and that continued looting through tens of billions in bonuses while on the government dole is entirely OK. This is a remarkably similar process to how al Anbar's (Iraq) guerrillas, fresh from slaughtering thousands of American soldiers, were able to secure autonomy, weapons, and a paycheck from the US gov't.
Think about climate change and the inability of the social system to even generate any meaningful response that wouldn't entail social bankruptcy.
