Samir Rihani refers in his book Complexity: An Appropriate Framework for Development to the “apparent stability of the communist system in eastern Europe…and its rapid collapse”  as an example of punctuated equilibrium in world affairs. Punctuated equilibrium in evolution—e.g., the explosion of mammalian species following the extinction of the dynosaurs–has become a relatively familiar concept in recent years, but the idea of applying it to world affairs strikes me as innovative. Moreover, it is instructive: just knowing that such shocking transformations are theoretically understandable serves as a warning to decision-makers everywhere to fear being blinded by hubris.
Of course, one need not adopt the vocabulary of complex adaptive systems to understand that empires come and go, but might even Toynbee not have benefited from the theoretical rigor of modern complexity theory? Up to a point, Toynbee’s analogy of empires that grow and decay like people losing their youthful vigor as they age is useful, but complexity theory leads more directly to clear analytical questions. Rather than empire as a creature fated eventually to age, with complexity theory, we view the empire as just one, albeit large, component in a greater—and interdependent–system, leading immediately to the question of how interaction with the other components influence the evolution of the empire, for nothing in a complex system is immutable.
Returning to the more specific issue of punctuated equilibrium, not only is nothing immutable, but change can be dammed up only to see the pressure released without warning. Let decision-makers be prepared.
And it is precisely complexity theory that can offer decision-makers some hope of being able to be prepared. Rihani usefully points out that “for a system to exist in a state of self-organized complexity, it must have internal elements capable of interacting at an appropriate level of connectivity and in accordance with suitable local rules.”  Imperial managers might well ask themselves if the foreign adventure they are contemplating will impair the functioning of the various connections and local rules that keep their empire healthy. Infringements of civil liberties in the U.S. in response to 9/11 and manipulative Wall Street behavior cheating small investors are examples that come to mind.
Rihani illustrates the kind of thinking we need if we are to develop the critical ability to diagnose the health of the global political system.