Anne-Marie Slaughter puts forth some analogies:
In plain English, the Cold War world was like chess. The 21st century world is more like tennis, where the wind, heat, possible rain delay (climactic factors that are themselves the product of complex adaptive systems), and your opponent's relative health and form on any given day (health and form that are themselves a function of whom your opponent has played prior to your match) all affect the speed, trajectory, and spin on the ball coming at you. Sometimes you get to choose your actions independently, for example when you serve, but mostly you adapt and respond. Or take surfing, where you really can't predict when the wave is coming or what it will look like. But when the conditions are right you can be sure that a wave will come and you can do a great deal to position and prepare yourself to ride it all the way — or at least not to get smashed under.